• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.430.1-430.1
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• 2014

According to advanced nanotechnology in the field of biomedical engineering, many studies of the interaction between topography of surfaces and cellular responses have been focused on nanostructure. In order to investigate this interaction, it is essential to make well-controlled nanostructures. Electron beam lithography (EBL) have been considered the most typical processes to fabricate and control nano-scale patterns. In this work, $TiO_2$ nanowire array was fabricated with hybrid process (top-down and bottom-up processes). Nanodot arrays were patterned on the substrate by EBL process (top-down). In order to control the spacing between nanodots, we optimized the EBL process using Poly(methyl methacrylate) (PMMA) as an electron beam resist. Metal lift-off was used to transfer the spacing-controlled nanodots as a seed pattern of $TiO_2$ nanowire array. Au or Sn nanodots which play an important role for catalyst using Vapor-Liquid-Solid (VLS) method were patterned on the substrate through the lift-off process. Then, the sample was placed in the tube furnace and heated at the synthesis temperature. After heat treatment, $TiO_2$ nanowire array was fabricated from the nanodots through VLS method (bottom-up). These results of spacing-controlled nanowire arrays will be used to study the interaction between nanostructures and cellular responses in our next steps.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.286-286
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• 2010

The lack of homogeneously sized single-walled carbon nanotubes (SWNTs) hinders their many applications because properties of SWNTs, in particular electrical conduction, are highly dependent on the diameter and chirality. Therefore, the preferential growth of SWNTs with predetermined diameters is an ultimate objective for applications of SWNTs-based nanoelectronics. It has been previously emphasized that a catalyst size is the one crucial factor to determine the CNTs diameter in chemical vapor deposition (CVD) process, giving rise to several attempts to obtain size-controllable catalyst by diverse methods, such as solid supported catalyst, metal-containing molecular nanoclusters, and nanostructured catalytic layer. In this work, diameter-controlled CNTs were synthesized using a nanostructured catalytic layer consisting of Fe/Al2O3/Si substrate. The CNTs diameter was controlled by structural modification of Al2O3 supporting layer, because Al2O3 supporting layer can affect agglomeration phenomenon induced by heat-driven surface diffusion of Fe catalytic nanoparticles at growth temperature.

• 전기화학회지
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• 제2권4호
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• pp.209-212
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• 1999

H-형의 분리 셀을 사용하여 중성 및 실온의 온화한 조건에서 조절 전위법 음전극 반응에 의한 nitroarene화합물들의 환원 짝지음 반응으로 높은 수율의 azobenzene유도체를 합성하였다. Pb또는 Pt cathode와 Pt anode를 사용하여 메탄을 용액 하에서 cyclic voltammetry에 근거하여 각 반응의 최적의 반응 조건을 결정한 후 반응을 실행하였으며, 대부분의 경우 환원 짝지음 반응은 치환기의 성질과 위치에 영향을 받지 않고 높은 수율로 성공적인 결과를 얻을 수 있었다.

• 동의생리병리학회지
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• 제34권3호
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• pp.117-125
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• 2020

The purpose of this review is to confirm whether Soyo-san (Xiaoyao-san) and its modifications is effective on alleviating clinical symptoms in chronic fatigue syndrome (CFS) patients. We collected clinical trials (randomized controlled trial, quasi-randomized controlled trial, controlled clinical trial) to investigate the effects of Soyo-san and its modifications on general symptoms, fatigue, depression and anxiety in CFS patients. The databases used for data retrieval were Pubmed, Central Cochrane, Embase, CNKI, CQVIP, Wanfang, CiNii, OASIS, RISS, and Koreamed. We performed selection/exclusion process from the found studies to conform with prespecified criteria, and assessed the final included trials according to the Cochrane risk of bias tool. The included studies were classified based on the interventions in experimental and control group. Eight randomized controlled trials and one controlled clinical trial (total 921 participants) were eligible and their results were synthesized in the meta analysis. The synthesis showed a considerable effect of Soyo-san and its modifications on improvement of general symptoms (relative risk 0.27 [95% CI 0.19 to 0.39], Z=7.03, P<0.00001; I2=0%) and fatigue severity (SMD -1.20 [95% CI -1.46 to -0.93], Z=8.78, P<0.00001; I2=52%) in CFS patients, while Effect on depression and anxiety were inconclusive. We found that Soyo-san and its modifications were effective for improvement of general symptoms and fatigue severity in CFS post-treatment.

• Bulletin of the Korean Chemical Society
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• 제28권10호
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• pp.1645-1650
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• 2007

This paper describes a racemic and stereoselective synthetic route for a novel cyclohexenyl carbocyclic adenine analogue. The required stereochemistry of the target compound was controlled using a stereoselective glycolate Claisen rearrangement followed by α-chelated carbonyl addition. The introduction of 6-chloropurine was achieved using Mitsunobu conditions, and further modifications of the corresponding heterocycle gave the target cyclohexenyl nucleoside.

• Bulletin of the Korean Chemical Society
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• 제30권9호
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• pp.2129-2131
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• 2009

• 한국세라믹학회지
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• 제25권5호
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• pp.509-517
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• 1988

The controlled Ti(CO2H5)4 hydrolysis reactions for the synthesis of Spherical Monodispersed Titania powders are described. Increasing the concentration of TEOT and the molar ratio of water to TEOT in alcohol solution decrease the reaction time and the particle size. The reaction time is delalyed by increasing the chain length and the number of carbon branches of alcohol as a solvent. The prepared powders with an average diameter of 0.8$\mu$ and the spherical monodispersed transfer to Rutile phase at 55$0^{\circ}C$.

• 한국세라믹학회지
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• 제34권12호
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• pp.1247-1253
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• 1997

Sinter-active yttria powders were prepared by a solution precipitation with using a self-decomposing precipitation agent NH2CONH2(urea). The cold-pressed powders can be sintered to full density and the microstructure of grains less than 200 nm at a temperature as low as 120$0^{\circ}C$. The activity of the yttria powder has been controlled by varying nucleation conditions during precipitation and by minimizing formation of aggregates. The type of precursor is decisive in preparation of a sinter-active oxide powder, and urea is desirable as a precipitation agent for an active yttrium oxide powder.

• 한국군사과학기술학회지
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• 제5권4호
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• pp.49-56
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• 2002

For the purpose of the increase in the performance and thermal stability of PBX's, the mixed formal consisting of BDNPF, DNPBF and BDNBF were synthesized. In order to find out the optimal condition for the synthesis of energetic plasticizer, BDNPF, DNPBF and BDNBF, the synthetic procedures have been investigated. We synthesized DNP-OH and DNB-OH through oxidative nitration and controlled various composition of mixed formal by $H_{2}SO_{4}$ and s-trioxane to investigate optimal composition, and then characterized its thermo-physical properties.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.200-200
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• 2006

Several polynorbornene or poly(norbornene-7-oxide) based functional block copolymers were synthesized by ring opening metathesis polymerization (ROMP) with good molecular weight and polydispersity control. Some representative functional groups in these polymers are a nitrobenzoyl group or ferrocene. These polymers were subjected to various chemical modification reactions to give other block copolymers that contain novel functionality such as amine, diazonium salt, and diazo groups. The resulting polymers were characterized by various techniques such as GPC, NMR, UV-VIS, AFM, and cyclovotammography (CV).