• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
• /
• pp.379.2-379.2
• /
• 2016

The Ni oxide/PVP nanofibers were synthesized by sol-gel and electrospinning technique. The obtained Ni oxide/PVP (polyvinylpyrrolidone) nanofibers were calcined to remove the PVP compound at 873 and 1173 K. The Ni oxide/PVP nanofibers were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The SEM images showed that the mat form was prepared by calcination of Ni oxide/PVP nanofibers at 873 K. And the crystal structure of Ni oxide at 1173 K was also confirmed by SEM images. XRD results shows the crystallinity of metallic Ni and NiO. TEM images also verified the crystal phase of Ni and Ni oxide. XP spectra revealed that the oxidation state of Ni to conclude the chemical composition of Cu oxide nanofibers.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2001년도 추계학술발표대회
• /
• pp.95-98
• /
• 2001

The effect of stabilizing polymer on hGM-CSF production was investigated in suspension cell cultures of transgenic tobacco. Secreted human GM -CSF from cell suspension cultures was detected in the medium at a maximum concentration of 180 ${\mu}g/L$ by ELISA. However, the secreted hGM -CSF was unstable in the medium, and rapidly degraded after day 5. In order to stabilize the secreted hGM-CSF, three stabilizing polymers were tested, polyethylene glycol, polyvinylpyrrolidone and gelatin. Gelatin was the most effective in stabilizing the secreted GM-CSF. Following the addition of 5% (w/v) gelatin, the maximum GM -CSF concentration reached 783 ${\mu}g/L$, a 4.6-fold increase over control.

• KSBB Journal
• /
• 제25권3호
• /
• pp.297-302
• /
• 2010

Ketoprofen is one of the propionic acid class of nonsteroidal anti-inflammatory drug with analgesic and antipyretic effects. The most common side effects from ketoprofen after oral administration are gastrointestinal irritation, diarrhea, abdominal pain and retention of fluid. Ketoprofen was formulated as water-soluble gels to reduce these side effects. To increase the skin permeability of ketoprofen, microsphere containing ketoprofen was prepared with chitosan and ploy-$\varepsilon$-caprolactone. And then prepared microsphere was manufactured as an adhesive hydrogel with polyvinylpyrrolidone K-25, polyethylene glycol 4000, and various permeation enhancers. The flux and permeability of ketoprofen were evaluated. As the concentration of tween 80 and enhancers increased, the flux of ketroprofen was accelerated. Also the permeation rate was facilitated by enhancers, but did not affect the lag time. From these results, the adhesive hydrogel using microsphere could be a good delivery system for ketoprofen to improve the skin permeation.

• Journal of Microbiology and Biotechnology
• /
• 제12권4호
• /
• pp.563-568
• /
• 2002

Stably transformed Drosophila melanogaster 52 cells producing recombinant VP7 were obtained, and recombinant VP7 expression was confirmed by Western blot analysis. The molecular weight of recombinant VP7 expressed in 52 cells was approximately 35.5 kDa, and 75% of the total VP7 produced was present in the medium. Recombinant VP7 contained N-linked glycosylated oligosaccharides. Aprotinin, leupeptin, and polyvinylpyrrolidone did not have any noticeable effect on recombinant VP7 production; however, DMSO and sodium butyrate increased its production by 120% and 60%, respectively.

• Journal of Pharmaceutical Investigation
• /
• 제18권2호
• /
• pp.43-47
• /
• 1988

In order to increase the dissolution characteristics of relatively water-insoluble metoclopramide (MCP), coprecipitates of MCP with polyvinylpyrrolidone (PVP), polyethylene glycol (PEG) 1000, 4000 or 6000 were prepared in various drug to polymer ratios. The dissolution rate of MCP-PVP coprecipitate was greater than those of MCP alone, MCP-PVP physical mixture and MCP-PEG coprecipitates. The dissolution rate of MCP-PEG 6000 coprecipitate was greater than those of MCP-PEG 1000 and MCP-PEG 4000 coprecipitates. The dissolution half-lives $(T_{50%})$ for MCP alone and 1:5 (w/w) MCP-PEG 6000 coprecipitate were determined by the log-probit method at $37^{\circ}C$ and found to be 4.17 and 0.98 min, respectively.

• Journal of Pharmaceutical Investigation
• /
• 제22권4호
• /
• pp.307-315
• /
• 1992

Dissolution rate of practically insoluble mefenamic acid was improved by roll mixing with sodium lauryl sulfate (SLS) or polyvinylpyrrolidone (PVP). The dissolution rate of the drug roll mixtures with SLS was superior to that of roll mixtures with PVP. The maximal dissolution rate was found in the roll mixtures system with SLS content of 60%. The dissolution rate of mefenamic acid roll mixtures with SLS content of 60% reached to the maximum value after 10 min of roll mixing. The transport of roll mixtures with SLS across rat jejunum was studied by the perfusion method using everted rat jejunum in vitro. The absorption rate of roll mixtures was superior to that of mefanamic acid.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2007년도 춘계학술대회
• /
• pp.216-219
• /
• 2007

Pulse current 전기 도금법을 사용해 균일하고 넓은 표면적을 갖는 Pt 나노구조가 제조되었다. 도금된 Pt 나노구조의 형태와 크기 분석을 위해 SFM과 TEM이 사용되었으며, 결정성 분석에는 XRD가 사용되었다. 고분자 첨가제를 첨가하여 도금되는 Pt의 크기를 제어할 수 있었는데, 순수한 Pt에 비해 첨가제의 영향으로 크기가 제어된 나노구조의 Pt들의 평균크기는 각각 3.4 nm와 2.9 nm로 순수한 Pt 360 nm의 것에 비해 훨씬 작아진 결과를 나타낼 뿐 아니라 크기가 제어된 나노구조 Pt는 메탄올 전기 산화반응에서도 순수한 Pt보다 뛰어난 촉매활성을 가짐을 보여주었다.

• 한국인쇄학회지
• /
• 제8권1호
• /
• pp.53-70
• /
• 1990

It is well known that viologens such as 1.1 - disubstituted 4, 4` - bipyridinium salts and those used as redox indicator, herbicide and electrocheromic display device because those possess the lowest redox potential in any organic system. Viologen salts produced reversible high blue color under the influence of radical cation by photoreduction This study is related to the synthesis of viologen derivatives and the photoreduction property in water solution stats and the polar aprotic polyvinylpyrrolidone(PVP) matrix.

• Journal of Pharmaceutical Investigation
• /
• 제14권1호
• /
• pp.1-10
• /
• 1984

Effects of water soluble carrier on the dissolution characteristics of indomethacin coprecipitates were investigated. Water soluble carriers used were polyvinylpyrrolidone, dextrose, mannitol and their mixtures of various ratios. The dissolution rates of indomethacin from coprecipitate with ratios of drug-to-carrier, kinds of carrier and ratios of carriers were as follows: 1. The dissolution rates increased proportionally to the ratios of carrier in the case of both single and combined carrier, and the dissolution rate of coprecipitate with the combined carrier was more rapid than that with single carrier. 2. The combined carrier of PVP-dextrose (1 : 2) in the case of the coprecipitate of drug-to carrier (1 : 1) and PVP-dextrose (4 : 1) in the case of the coprecipitate of drug-to carrier (1 : 3) yield the most rapid dissolution rate. 3. The dissolution rate of indomethacin was the most markedly enhanced in the case of the combined carrier of PVP and dextrose.

• Bulletin of the Korean Chemical Society
• /
• 제35권11호
• /
• pp.3209-3212
• /
• 2014

This paper describes a selective synthetic method of fabricating Ag nanowires by using a modified polyol process. To synthesize the Ag nanowire, an ethylene glycolic solution of silver nitrate and an ethylene glycolic solution of polyvinylpyrrolidone solution containing a small amount of organic oxidant, 1,4-benzoquinone, were slowly added to a hot ethylene glycol medium at $160^{\circ}C$ for 8 min using a syringe pump. The reaction mixtures were heated for an additional 45 min and cooled to room temperature. Finally, the silver nanomaterials were isolated from the mixture by centrifugation. The crystal structure of the nanomaterials was investigated by powder X-ray diffraction analyses, and their morphology was investigated by scanning electron microscopy. A small amount of organic oxidant, 1,4-benzoquinone, played a significant role in controlling the morphology during crystal growth. Consequently, Ag nanowires rather than Ag nanoparticles were selectively obtained.