• Development and Reproduction
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• v.12 no.3
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• pp.267-274
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• 2008

Differentiation of blastocyst is critical step for implantation and is under the control of regulation factors originated from embryo or reproductive tracts. The sequential communication with those factors is suspected as critical events for differentiation. It has been suggested that intracellular signaling pathways activated by calcium is essential in differentiation of blastocyst. Previously, it was known that concanavalin A (Con A) increase the levels of free calcium in blastocyst stage. However, Con A can not accelerate the hatching, although heparin-binding epidermal growth factor-like growth factor (HB-EGF), a modulator of calcium level, accelerate the hatching of blastocyst. In this study, it was investigated whether Con A or prostaglandin $E_2$ ($PGE_2$) can modulate the differentiation of blastocyst. Con A accelerated the expansion of blastocyst in both 1 hr pulse treatment group and continuous treatment group. However, Con A significantly suppressed the hatching in both groups. The inhibition was significantly strong in continuous treatment group compared with 1 hr pulse treatment group. On the other hand, $PGE_2$ induced the increase the free calcium level, but did not accelerate the expansion. In addition $10{\mu}m\;PGE_2$ inhibited hatching. However, $PGE_2$ could accelerate hatching in Con A pretreated blastocyst. $PGE_2$ also caused the increase of free calcium level in Con A pretreated blastocyst. From these results, it is suggested that changes of the free calcium level induce a different calcium-mediated signaling pathways. In addition, sequential stimulation by signal molecules may triggers the cellular mechanisms for the differentiation of blastocyst.

• Journal of Life Science
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• v.20 no.7
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• pp.1093-1099
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• 2010

Little is known about the cardiovascular effects of Lycopene, an anti-cancer and anti-oxidative agent. In this study, we executed a series of experiments with vascular endothelial cells to disclose the cardiovascular functions of lycopene. From our in vitro experiments, lycopene was determined to act as a stimulant to induce endothelial cell proliferation and migration. In addition, lycopene was shown to inhibit lipopolysaccharide (LPS)-induced adhesion of THP-1 leukocytes to endothelial cells, as well as activating mitogen activated protein kinase (MAPK) family members, ERK, JNK and p38 MAPK. Both ERK and p38 MAPK were involved in lycopene-induced cell proliferation, while JNK was involved in lycopene-dependent cell migration. Taken together, lycopene activates MAPK family members which regulate cell proliferation and migration. Lycopene differentially blocks LPS-dependent adhesion for THP-1 to endothelial cells, indicating that lycopene is likely to regulate a variety of vascular functions.

• The Korean Journal of Food And Nutrition
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• v.28 no.4
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• pp.579-585
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• 2015

Rutin is a well-known flavonoid found in buckwheat. Recent studies have demonstrated that the biological actions of rutin include anti-inflammatory and anti-cancer effects, but the underlying molecular mechanisms of these actions are not yet fully understood. Neoplastic cell transformation is considered a major event that contributes to carcinogenesis, and the present study aimed to determine whether rutin would exert anti-tumor effects via the results suggest that rutin exerted a potent inhibitory influence on the molecular activity of the MEK/ERK and MKK4/JNK pathways and strongly attenuated EGF-induced neoplastic cell transformation. These findings provide insight into the biological actions of rutin and the molecular basis for the development of new chemoprotective agents.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.4 s.54
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• pp.311-321
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• 2005

Tea (Camellia sinenis) is a popular beverage consumed worldwide. Since green tea, mainly consumed in Asia, has various biological activities, green tea components became one of the most favorite candidates as a functional materials for cosmetics and functional foods. The biological activities of green tea for skin cue have been ranged from protection of epidermal cells to the stimulation of extracellular matrix (ECM) biosynthesis. Green tea polyphenols (GTPs), which are active ingredients of green tea, possess anti-inflammatory, anti-carcinogenic and immune potentiation properties as well as antioxidant. They also modulate intracellular signal transduction pathways. GTPs decrease ultraviolet (UV)-induced oxidative stress, thus suppress mitogen-activated protein kinase (MAPK) pathway and apoptosis in keratinocytes. In addition, GTPs prevent the Induction of inflammatory mediators, such as cyclooxygenase-2 (COX-2), interleukin-8 (IL-8), and vascular endothelial growth factor (VEGF) by tumor necrosis factor alpha $(TNF{\alpha})$ or chemical treatment in keratinocytes. GTPs treatment protects from chemical-or UV-induced skin tumor incidence in animal experiment. Besides, GTPs stimulate keratinocyte differentiation and proliferation of normal and aged epidermal cells, resectively, and suppress matrix metalloproteinases (MMPs) release. According to the progress of formulation study, green tea components will be guaranteed materials for the more effective skin cue products.

• Membrane Journal
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• v.27 no.3
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• pp.205-215
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• 2017

Polymer membranes are cheap and easy in fabrication, and show a high permeability and selectivity, thus play pivotal roles in gas separation as well as water purification. However, polymer membranes typically exhibit the trade-off relation between permeability and selectivity; i.e. when the permeability is high, the selectivity is low and vice versa. Facilitated transport has been considered one of the solutions to address this issue. Over the last decades, facilitated transport concept had played an important role in preparing the membranes and providing ideal and various models for the transport. Understanding the nature of carrier, the mobility of matrix and the physico-chemical properties of polymer composites are crucial for facilitated transport. Depending on the mobility of carrier, facilitated transport membrane is classified into three; mobile carrier membrane, semi-mobile carrier membrane, fixed-site carrier membrane. Also, there are four types of reversible reaction between the carrier and the specific target; proton transfer reaction, nucleophilic addition reaction, p-complexation reaction and electrochemical reaction. The facilitated transport membranes have been applied in the separation of CO2, O2 and olefin (propylene or ethylene). In this review, major challenges surrounding facilitated transport membranes and the strategies to tackle these challenges are given in detail.

• Journal of the korean veterinary medical association
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• v.35 no.3
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• pp.198-205
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• 1999

유럽연합의회는 1998년 12월 17일 사료첨가물에 관한 유럽의회규정(Council Directive 70/524/EEC, `70. 11. 23)을 개정(Council Regulation EC 2821/98)하여 그동안 사료첨가용으로 사용을 허용하였던 항생물질 중 아연바시트라신, 스피라마이신, 인산타일로신 및 버지니아마이신 등 4종의 사용을 금지하였다. 그러나 풀라보포스포리폴(풀라보마이신), 모넨신소디움, 살리노마이신소디움, 아빌라마이신 등 4종의 사료첨가용 항생물질은 계속 사용이 허용된다. 축산식품의 안전성이 강조되고 있는 가운데 유럽연합의 이러한 조치는 축산분야에 종사하는 사람들에게 커다란 관심을 갖게 하고있다. 이 글은 유럽연합이 4종의 항생물질을 사료첨가용으로 사용을 금지하게된 배경을 살펴봄으로서 유럽연합의 사료첨가용 항생제 사용금지에 관한 정확한 내용을 파악하는데 도움을 드리기 위하여 작성되었다. 유럽연합의 아연바시트라신, 스피라마이신, 인산타일로신 및 버지니아마이신 등 4종의 항생제에 대한 이러한 사용금지 조치는 가축의 성장촉진용으로 사용되는 이러한 항생물질에 내성을 획득한 가축의 세균이 인체에 기생하는 세균에게 그 내성을 전달하여 인체용으로 사용되는 관련 약품들에 대하여 내성을 일으켜 사람에서의 질병 치료를 어렵게 함으로서 인체의 건강을 해할 우려가 있다는 전제하에서 실시되었다. 이러한 조치는 현재까지 확실한 증거가 나타나지는 않았으나, 그 위험을 배제할 수 없으므로 이러한 위험을 예방하는 차원에서 이루어지는 예방적 조치이며, 따라서 금번의 사용금지 조치는 유럽연합 집행위원회에서 2000년 12월 31일 이전까지 이러한 항생제의 내성 유발에 관한 여러 가지 연구와 항생제 투여동물에서의 미생물 내성 감시 프로그램의 결과에 따라 재검토될 것을 규정하고 있다. 금번 사용금지 조치된 4종의 항생제는 그 동안 우리나라에서도 그 유효성과 안전성이 인정되어 축산 현장에서 사용되어온 물질들이다. 금번 유럽연합의 조치는 우리나라에서도 이러한 항생제들에 대한 재평가의 필요성을 제기하는 것으로서 이 분야에 종사하는 산업계, 학계, 연구계가 모두 힘을 모아 조속한 기간 내에 그 안전성을 재평가하여 축산식품에서의 안전성을 확보하도록 노력하여야할 것이다.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.782-789
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• 2001

Local heat/mass transfer and friction loss in a square duct roughened with various types of continuous and discrete rib turbulators are investigated. The combined effects of the gap flows of the discrete ribs and the secondary flows are examined for the purpose of the reduction of thermally weak regions and the promotion of the uniformity of heat/mass transfer distributions as well as the augmentation of average heat/mass transfer. The rib-to-rib pitch to the rib height ratio (p/e) of 8 and the rib angles of 90 and 60 deg are selected with $e/D_{h}=0.08$. The vortical structure of the secondary flows induced by the parallel angled arrays are quite distinct from that induced by the cross angled arrays. This distinction influences on heat/mass transfer and friction loss in all the tested cases. The gap flows of the discrete ribs reduce the strength of the secondary flows but promote local turbulence and flow mixing. As a result, the fairly uniform heat/mass transfer distributions are obtained with two row gaps.

• Applied Chemistry for Engineering
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• v.16 no.1
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• pp.15-20
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• 2005

Many scientists have been interested in drug delivery system (DDS) which improves medical treatment for curing a disease. Transdermal drug delivery (TDD) that is one of the DDS offers several advantages over the traditional methods. For this reason, the study of TDD has been investigated in various field. In this paper, principle of transdermal delivery and penetration enhancers into the skin including in vitro and in vivo data have been studied.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.335-340
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• 2005

Nonlinear and forced oscillations of supported viscous droplet were focused in the present study. The droplet has a free contact line with solid plate and inviscid fluid. Natural frequencies of a pendant droplet have been investigated experimentally by imposing the acoustic wave while the frequency is being increased at a fixed amplitude. The evaporation was observed at atmosphere pressure. The droplet was recorded throughout the entire evaporation process and transient variations of the volume was measured. The evaporation process of oscillating droplet with thermofoil has been also observed to investigate analyzing the resonance effect on the thermal characteristics of droplet. It is found that a pendant droplet shows the resonant behaviors at each mode similar to the theoretical analysis. During imposing the acoustic wave, the pendant droplet makes a rotating motion in its longitudinal axis which is a new shape oscillation mode. The evaporation rate of a pendant droplet at resonant frequency is significantly enhanced.

• Journal of Life Science
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• v.20 no.8
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• pp.1249-1253
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• 2010

Sericin is a type of high molecular weight water-soluble glycoprotein surrounding fibroin (silk protein) that has been used as a cell culture supplement and accelerates cell proliferation in various serum-free media. The purpose of this study was to investigate the enhancing effect of thyroglobulin (Tg) secretion by sericin in thyrocytes, FRTL-5 cells. While Tg-mRNA expression was not enhanced, a secreted form of Tg was obviously increased by sericin. In this status, expression of both endoplasmic reticulum (ER) molecular chaperones (Bip & calreticulin) and ER membrane proteins (IRE1, PERK & ATF6) was enhanced. The proximal step of IRE1, XBP1 mRNA splicing was slightly detected however, the proximal step of PERK, phosphorylation of $eIF2{\alpha}$, was changeless. In addition, sericin enhanced cell viability by the MTT assay. The above results showing the ability of sericin to promote protein production demonstrated its potential usefulness as a new biomaterial.