• 한국결정성장학회지
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• 제16권6호
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• pp.256-259
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• 2006

Vapor phase epitaxy(VPE)법을 사용하여 amorphous $SiO_x$. nanowires를 성장시켰다. Ni thin film을 촉매로 사용하여 Si 기판위에 $800{\sim}1100^{\circ}C$ 범위의 온도에서 성장시켰으며, $SiO_x$ nanowires의 성장 메커니즘은 Vapor-liquid-solid(VLS)으로 확인되었다. $SiO_x$ nanowires의 shape와 morphology는 scanning electron microscope(SEM)으로 분석하였으며, cotton-like형태이고 길이는 $10{\mu}m$정도였다. 그리고 구조적 특징은 transmission electron microscope(TEM)으로 관찰하였고, $SiO_x$ nanowires의 성분 분석은 energy dispersed X-ray spectroscopy(EDS)로 하였다. EDX spectrum으로 nanowires가 Si와 O로 구성되어졌음을 확인하였다.

• Korean Chemical Engineering Research
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• 제51권4호
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• pp.470-475
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• 2013

초음파-용매열 혼합방법으로 염화지르코늄과 1,4-benzenedicarboxylic acid를 사용하여 다공성 금속유기 구조체인 UiO-66을 1-L 규모로 제조하였다. 합성 개시 2시간 뒤 약 $0.2{\mu}m$의 작고 고른 형태와 $1,375m^2/g$의 높은 비표면적을 갖는 결정을 95%의 높은 수율로 얻을 수 있었다. 제조된 UiO-66 물질의 이산화탄소 흡착 거동을 조사한 결과, 1기압 273 K 및 298K에서 각각 198 및 84 mg/g의 흡착량과 32:1 이상의 높은 질소 대비 이산화탄소 흡착 선택성을 갖는 것을 확인하였다. 흡착이 진행됨에 따라 흡착열은 33에서 25 kJ/mol 로 감소하였다. 또한 UiO-66 물질을 사용하여 액상 회분식 조건에서 자일렌 이성체의 분리 연구를 수행하였으며, o-자일렌이 단일성분 최대 흡착능 및 경쟁흡착에서도 m-, p-자일렌 대비 약 2배 이상의 높은 흡착 선호도를 갖는 것을 확인할 수 있었다.

• 한방안이비인후피부과학회지
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• 제27권1호
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• pp.58-67
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• 2014

Objective : Lycii Fructus Extracts(LFE) can do Anti-hypertension activity, Antidepressant, Anti-diabetic activity. This study was designed to investigate effects of LFE on skin whitening and elasticity using melanoma cells. Methods : In this experiment, effect of LFE on cell viability, inhibition of melanin synthesis and inhibitory effect on tyrosinase and elastase. Results : More than $250{\mu}g/ml$ of LFE treated group showed lowered proliferation rates significantly compared to non-treated group. More than $125{\mu}g/ml$ of LFE treated groups were lower levels of melanin synthesis respectively. LFE showed inhibitory effect on tyrosinase activities in vitro. And, LFE suppressed tyrosinase activities in B16F10 cells significantly. Finally, LFE suppressed elastase type I and IV activities in dose-dependent manner in vitro. And LFE also slightly suppressed elastase activities in vivo. Conclusion : These results suggest that LFE can inhibit melanin synthesis through ihhibitory action on tyrosinase activity and inhibt elastase activity, and also suggest that these results can be used for the study on maintaining skin elasticity or whitening.

• 생명과학회지
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• 제17권1호
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• pp.105-109
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• 2007

참나무 목초액은 예로부터 농축산업에 이용되어 왔으며 최근에는 항균 및 항산화 효과가 있는 것으로 밝혀지면서 목초액에 대한 과학적인 연구가 활발히 진행되고 있다. 참나무 목초액의 항균 및 항산화 활성과 면역기능에 미치는 영향을 조사하였다. 참나무 목초액의 항균활성은 식품 부패균 및 치주질환 원인균에 대하여 항균활성을 조사하였는데 목초액 $50{\mu}l$ 첨가시 대부분의 식품부패균 및 치주질환 원인균의 생육이 현저히 저해되었다. 참나무 목초액의 항산화력은 DPPH법에서 $20{\mu}l$ 첨가시 95%의 라디칼 소거능을 보였으며 SOD유사활성은 $50{\mu}l$ 첨가시 65%의 항산화력을 나타내었다. 참나무 목초액의 항염증효과는 세균의 LPS를 처리하여 유도된 RAW264.7 세포에서 조사되었는데 LPS를 처리하여 유도된 NO 활성을 현저히 감소(86%)시켰으며 이 농도에서 세포독성 없이 높은 면역 효과를 나타내었다.

• 전력전자학회논문지
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• 제16권4호
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• pp.317-325
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• 2011

본 논문에서는 단상 UPS 인버터의 강인한 전압제어기를 제안하고 설계한다. 제안된 전압제어기는 부하 변동에 대해서 강인 안정성과 강인 추종 성능을 얻기 위해 ${\mu}$-합성에 기초한 강인 제어 이론을 이용하여 설계되었다. 설계된 전압제어기의 강인 제어 성능은 ${\mu}$-해석을 통해 이론적으로 확인하였다. 그리고 단상 인버터에 대해 선형 부하와 비선형 부하로 시뮬레이션 및 실험을 수행하여 제안된 전압제어기가 안정된 전압제어 성능과 빠른 동특성을 가지는 향상된 제어성능을 제공하는 것을 확인하였다.

• Journal of Dairy Science and Biotechnology
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• 제37권2호
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• pp.136-153
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• 2019

The present study aimed to investigate the effects of skin care foods on the synthesis of pro-collagen type I C peptide and suppression of matrix metalloproteinase (MMP)-1 secretion through an in vitro study using fibroblasts (Hs68 cells) and keratinocytes (HaCaT cells). Among the three skin care foods developed in this study, three beans cookie and avocado yoghurt influenced the production of pro-collagen type I C peptide and suppressed MMP-1 secretion; however, tiger nut Galsu drink did not exhibit these effects. All skin care foods, including three beans cookie and plain yoghurt ($50{\mu}g/mL$, p<0.001) influenced the suppression of MMP-1 in addition to other commercially available breast milk production support foods examined, such as Heath Heather ($50{\mu}g/mL$, p<0.001), Happy Mama ($50{\mu}g/mL$, p<0.01), BioLys ($50{\mu}g/mL$, p<0.001), Enfamama ($25{\mu}g/mL$, p<0.0001), and Pregnagen ($25{\mu}g/mL$, p<0.001). Avocado fruit yoghurt ($25{\mu}g/mL$, p<0.05), avocado fruit jam yoghurt ($50{\mu}g/mL$, p<0.01), Enfamama ($100{\mu}g/mL$, p<0.05), and Pregnagen ($100{\mu}g/mL$, p<0.05) influenced the production of pro-collagen type I C peptide and suppressed MMP-1 secretion. This result indicates that only avocado jam yoghurt significantly influenced both the prevention of skin keratinization and acceleration of recovery of skin fibrous structure. Therefore, avocado is a favorable ingredient for nutrition-balanced dietary foods or an essential ingredient in products for revitalization of human skin.

• Asian-Australasian Journal of Animal Sciences
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• 제27권3호
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• pp.414-421
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• 2014

This study was conducted to determine the effects of saturated long-chain fatty acids (LCFA) on cell proliferation and triacylglycerol (TAG) content, as well as mRNA expression of ${\alpha}s1$-casein (CSN1S1) and genes associated with lipid and protein synthesis in bovine mammary epithelial cells (BMECs). Primary cells were isolated from the mammary glands of Holstein dairy cows, and were passaged twice. Then cells were cultured with different levels of palmitate or stearate (0, 200, 300, 400, 500, and 600 ${\mu}M$) for 48 h and fetal bovine serum in the culture solution was replaced with fatty acid-free BSA (1 g/L). The results showed that cell proliferation tended to be increased quadratically with increasing addition of stearate. Treatments with palmitate or stearate induced an increase in TAG contents at 0 to 600 ${\mu}M$ in a concentration-dependent manner, and the addition of 600 ${\mu}M$ was less effective in improving TAG accumulation. The expression of acetyl-coenzyme A carboxylase alpha, fatty acid synthase and fatty acid-binding protein 3 was inhibited when palmitate or stearate were added in culture medium, whereas cluster of differentiation 36 and CSN1S1 mRNA abundance was increased in a concentration-dependent manner. The mRNA expressions of peroxisome proliferator-activated receptor gamma, mammalian target of rapamycin and signal transducer and activator of transcription 5 with palmitate or stearate had no significant differences relative to the control. These results implied that certain concentrations of saturated LCFA could stimulate cell proliferation and the accumulation of TAG, whereas a reduction may occur with the addition of an overdose of saturated LCFA. Saturated LCFA could up-regulate CSN1S1 mRNA abundance, but further studies are necessary to elucidate the mechanism for regulating milk fat and protein synthesis.

• Restorative Dentistry and Endodontics
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• 제20권1호
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• pp.275-288
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• 1995

The inhibitory effect of cell wall extracts of streptococci, have been investigated to know host-parasite relationship or pathogenesis of abscess formation. Streptococci isolated from the infected root canals were sonicated to get cell wall extracts which have been known as one of the factors of pyogenesis. Lymphocytes separated by density gradient were stimulated with phytohemagglutinin and exposed to cell wall extracts of Streptococcus sanguis, S. mitis, S. uberis, S. mutans (ATCC 10449), and S. faecalis (ATCC 19433). [$^3H$]-thymidine uptake of lymphocytes was analyzed with scintillation counter and lactate dehyrogenase (LD) activity was measured with autochemistry analyzer. S. faeealis had the strongest inhibitory effect. beginning at $100\;{\mu}g/ml$ concentration of sonic extracts. S. sanguis and S. mitis had inhibitory effect at $300\;{\mu}g/ml$, while S. uberis and S. mutans showed no inhibitory, effect on DNA syntheis even at $300\;{\mu}g/ml$. Each streptococci showed different inhibitory effect on the DNA synthesis of lymphocytes, which finding indicated wide spectrum of susceptibility of lymphocytes according to streptococcus spp. There were no significant difference of LD activities between control and each streptococcal extracts. Streptococcal sonic extracts did not affect the morphological findings or number of colonies activated lymphocytes. These finding suggested the inhibitory effect of sonic extract of streptococci to lymphocytes could be detected by DNA synthesis inhibition, not by cellular membrane damage.

• Animal cells and systems
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• 제2권3호
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• pp.383-388
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• 1998

A RecA-like protein (RecAps) was identified from fluorescent Pseudomonas sp. and the inducible nature of the protein was characterized in detail. It was shown by dose-response and time-course experiments using two DNA damaging agents, nalidixic acid and mitomycin-C, that the cellular level of RecAps protein was increased 3-8 fold compared to that of the control. The most effective doses of nalidixic acid and mitomycin-C for the protein induction were $30{\mu}g/ml$ and $0.3{\mu}g/ml$ at the treatment time point of 150 min, respectively. The enhanced level of RecAps protein was gradually decreased to the control level after 10 hr in normal medium. Interestingly, the cellular level of RecAps protein was increased by the same DNA damaging agents even when cell growth was completely inhibited by treatment with $170{\mu}g/ml$ of chloramphenicol, an inhibitor of protein synthesis, suggesting that new protein synthesis is not required for the induction of RecAps. All these results suggest that a typical S0S repair function driven by RecA-like protein is conserved in Pseudomonas sp. cells as in E, coli.

• 한국자원식물학회지
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• 제30권3호
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• pp.272-279
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• 2017

EP was obtained through 20% ethanol extraction of Pueraria lobata root, and the fermented form of EP, FEP, was prepared from the EP after incubating with Lactobacillus rhamnosus vitaP1. There was no significant toxicity by EP and FEP up to $1000{\mu}g/ml$ in NIH-3T3, HaCaT, and B16F10 cells. In addition to antioxidant potentials of EP and FEP determined by DPPH and ABST assays, we confirmed increase of procollagen type I and elastin synthesis by supplementation of the EP and FEP at the concentration of $50{\mu}g/ml$ using ELISA kits. The protein expression levels of matrix metalloprotease (MMP)-1, -3, and -9, those are involved in the degradation of collagen or other skin matrix proteins, were remarkably suppressed while their inhibitory protein metallopeptidase inhibitor 1 (TIMP-1) was greatly up-regulated by supplementation of the EP and FEP at a concentration of $50{\mu}g/ml$. Taken together, both EP and FEP supplementation could be involved in the suppression of the skin wrinkle formation through inhibiting degradation of collagen and stimulating the synthesis of collagen and elastin. The results showed that the anti-wrinkle potential of the EP and FEP will be a promising candidate for developing cosmeceutical compounds or products.