• Title/Summary/Keyword: barrier function

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Built-in voltage in organic light-emitting diodes from the measurement of modulated photocurrent (변조 광전류 측정법을 이용하여 전극 변화에 따른 유기발광소자의 내장 전압)

  • Lee, Eun-Hye;Yoon, Hee-Myoung;Han, Wone-Keun;Kim, Tae-Wan;Ahn, Joon-Ho;Oh, Hyun-Seok;Jang, Kyung-Uk;Chung, Dong-Hoe
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.51-52
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    • 2007
  • Built-in voltage in organic light-emitting diodes was studied using modulated photocurrent technique ambient conditions. From the bias voltage-dependent photocurrent, built-in voltage of the device is determined. The applied bias voltage when the magnitude of modulated photo current is zero corresponds to a built-in voltage. Built-in voltage in the device is generated due to a difference of work function of the anode and cathode. A device was made with a structure of anode/$Alq_3$/cathode to study a built-in voltage. ITO and ITO/PEDOT:PSS were used as an anode, and Al and LiF/AI were used as a cathode. It was found that an incorporation of PEDOT:PSS layer between the ITO and $Alq_3$ increases a built-in voltage by about 0.4V. This is consistent to a difference of a highest occupied energy states of ITO and PEDOT:PSS. This implies that a use of PEDOT:PSS layer in anode improves the efficiency of the device because of a lowering of anode barrier height. With a use bilayer cathode system LiF/Al, it was found that the built-in voltage increases as the LiF layer thickness increases in the thickness range of 0~1nm. For 1nm thick LiF layer, there is a lowering of electron barrier by about 0.2eV with respect to an Al-only device. It indicates that a very thin alkaline metal compound LiF lowers an electron barrier height.

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Involvement of a Novel Organic Cation Transporter in Paeonol Transport Across the Blood-Brain Barrier

  • Gyawali, Asmita;Krol, Sokhoeurn;Kang, Young-Sook
    • Biomolecules & Therapeutics
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    • v.27 no.3
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    • pp.290-301
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    • 2019
  • Paeonol has neuroprotective function, which could be useful for improving central nervous system disorder. The purpose of this study was to characterize the functional mechanism involved in brain transport of paeonol through blood-brain barrier (BBB). Brain transport of paeonol was characterized by internal carotid artery perfusion (ICAP), carotid artery single injection technique (brain uptake index, BUI) and intravenous (IV) injection technique in vivo. The transport mechanism of paeonol was examined using conditionally immortalized rat brain capillary endothelial cell line (TR-BBB) as an in vitro model of BBB. Brain volume of distribution (VD) of [$^3H$]paeonol in rat brain was about 6-fold higher than that of [$^{14}C$]sucrose, the vascular space marker of BBB. The uptake of [$^3H$]paeonol was concentration-dependent. Brain volume of distribution of paeonol and BUI as in vivo and inhibition of analog as in vitro studies presented significant reduction effect in the presence of unlabeled lipophilic compounds such as paeonol, imperatorin, diphenhydramine, pyrilamine, tramadol and ALC during the uptake of [$^3H$]paeonol. In addition, the uptake significantly decreased and increased at the acidic and alkaline pH in both extracellular and intracellular study, respectively. In the presence of metabolic inhibitor, the uptake reduced significantly but not affected by sodium free or membrane potential disruption. Similarly, paeonol uptake was not affected on OCTN2 or rPMAT siRNA transfection BBB cells. Interestingly. Paeonol is actively transported from the blood to brain across the BBB by a carrier mediated transporter system.

Enhancement of skin barrier and hydration-related molecules by protopanaxatriol in human keratinocytes

  • Lee, Jeong-Oog;Hwang, So-Hyeon;Shen, Ting;Kim, Ji Hye;You, Long;Hu, Weicheng;Cho, Jae Youl
    • Journal of Ginseng Research
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    • v.45 no.2
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    • pp.354-360
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    • 2021
  • Background: Protopanaxatriol (PPT) is a secondary intestinal metabolite of ginsenoside in ginseng. Although the effects of PPT have been reported in various diseases including cancer, diabetes and inflammatory diseases, the skin protective effects of PPT are poorly understood. Methods: HaCaT cells were treated with PPT in a dose-dependent manner. mRNA and protein levels which related to skin barrier and hydration were detected compared with retinol. Luciferase assay was performed to explore the relative signaling pathway. Western blot was conducted to confirm these pathways and excavated further signals. Results: PPT enhanced the expression of filaggrin (FLG), transglutaminase (TGM)-1, claudin, occludin and hyaluronic acid synthase (HAS) -1, -2 and -3. The mRNA expression levels of FLG, TGM-1, HAS-1 and HAS-2 were suppressed under NF-κB inhibition. PPT significantly augmented NF-κB-luc activity and upregulated Src/AKT/NF-κB signaling. In addition, PPT also increased phosphorylation of the mitogen-activated protein kinases (MAPKs) ERK, JNK and p38 and upstream MAPK activators (MEK and MKK). Furthermore, transcriptional activity of AP-1 and CREB, which are downstream signaling targets of MAPK, was enhanced by PPT. Conclusion: PPT improves skin barrier function and hydration through Src/AKT/NF-κB and MAPK signaling. Therefore, PPT may be a valuable component for cosmetics or treating skin disorders.

BIM-based Design Automation Tool and Digital Twin Interoperability - Case of the Next Generation Noise Barrier Tunnel - (BIM 기반 설계 자동화 도구와 디지털 트윈의 상호운용성 - 차세대 방음터널의 사례를 중심으로 -)

  • Yang, Seung-Won;Kim, Seong-Jun;Kim, Sung-Ah
    • Journal of KIBIM
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    • v.11 no.4
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    • pp.31-41
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    • 2021
  • Digital twins between "BIM Digital Model-Physical Prototype Model" will be built for Noise Barrier tunnel(NBT) that meet the definition of N.G smart city facilities derived from previous studies to build a data flow that connects data at each stage of design, construction, and operation. In this process, BIM design automation tools are created and utilized, and consistent transmission of member and attribute data is performed by converting them into IFC format. Through this, the purpose is to improve the labor-intensive environment required from the design stage of the NBT and to consistently maintain the information required for subsequent production and construction. This includes achieving changes in the construction industry based on digital transformation by unifying various data formats used differently for each industry from design to operation. In addition, it demonstrates that information exchange in the maintenance and management stages is possible based on the data exchange of the established digital twin and aims to improve the existing labor-intensive environment and expand operability between digital and physical information. As suggested in previous studies, the implementation of digital twins in these N.G smart city facilities includes the possibility of building an environment that adds to the possibility of high value-added product platforms as well as the function of big data platforms targeting existing smart cities.

The Effects of Glucagon-like Peptide-2 on the Tight Junction and Barrier Function in IPEC-J2 Cells through Phosphatidylinositol 3-kinase-Protein Kinase B-Mammalian Target of Rapamycin Signaling Pathway

  • Yu, Changsong;Jia, Gang;Deng, Qiuhong;Zhao, Hua;Chen, Xiaoling;Liu, Guangmang;Wang, Kangning
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.5
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    • pp.731-738
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    • 2016
  • Glucagon-like peptide-2 (GLP-2) is important for intestinal barrier function and regulation of tight junction (TJ) proteins, but the intracellular mechanisms of action remain undefined. The purpose of this research was to determine the protective effect of GLP-2 mediated TJ and transepithelial electrical resistance (TER) in lipopolysaccharide (LPS) stressed IPEC-J2 cells and to test the hypothesis that GLP-2 regulate TJ and TER through the phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt)-mammalian target of rapamycin (mTOR) signaling pathway in IPEC-J2 cells. Wortmannin and LY294002 are specific inhibitors of PI3K. The results showed that $100{\mu}g/mL$ LPS stress decreased TER and TJ proteins occludin, claudin-1 and zonula occludens protein 1 (ZO-1) mRNA, proteins expressions (p<0.01) respectively. GLP-2 (100 nmol/L) promote TER and TJ proteins occludin, claudin-1, and zo-1 mRNA, proteins expressions in LPS stressed and normal IPEC-J2 cells (p<0.01) respectively. In normal cells, both wortmannin and LY294002, PI3K inhibitors, prevented the mRNA and protein expressions of Akt and mTOR increase induced by GLP-2 (p<0.01) following with the significant decreasing of occludin, claudin-1, ZO-1 mRNA and proteins expressions and TER (p<0.01). In conclusion, these results indicated that GLP-2 can promote TJ's expression and TER in LPS stressed and normal IPEC-J2 cells and GLP-2 could regulate TJ and TER through the PI3K/Akt/mTOR pathway.

Analysis of Threshold Voltage Characteristics for Double Gate MOSFET Based on Scaling Theory (스켈링이론에 따른 DGMOSFET의 문턱전압 특성분석)

  • Jung, Hak-Kee;Han, Ji-Hyung;Jeong, Dong-Soo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2012.05a
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    • pp.683-685
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    • 2012
  • This paper have presented the analysis of the change for threshold voltage and drain induced barrier lowering among short channel effects occurred in subthreshold region for double gate(DG) MOSFET with two gates to be next-generation devices, based on scaling theory. To obtain the analytical solution of Poisson's equation, Gaussian function been used as carrier distribution to analyze closely for experimental results, and the threshold characteristics have been analyzed for device parameters such as channel thickness and doping concentration and projected range and standard projected deviation of Gaussian function. Since this potential model has been verified in the previous papers, we have used this model to analyze the threshold chatacteristics. As a result to apply scaling theory, we know the threshold voltage and drain induced barrier lowering is changed, and the deviation rate is changed for device parameters for DGMOSFET.

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Effect of Insamyangyoung-tang on the TEWL of High Dose Steroid Injected Hairless Mice (인참양영탕(人參養榮湯)이 장기간 고용량 스테로이드 투여 hairless mice의 피부장벽에 미치는 영향)

  • Nam, Hae-Jeong;Kim, Yoon-Bum
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.21 no.2
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    • pp.19-27
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    • 2008
  • Objective : The side effect of prolonged use of topical corticosteroids to skin is well-known. Moreover, resent studies have shown that prolonged use of systemic corticosteroids also negatively impacts skin barrier function. Corticosteroids have a major role in the practical management of many variable conditions. So, it is important to find the drug or the method which could protect the skin from the damage caused by corticosteroids. At former study, we investigated that Insamyangyoung-tang has some effect on skin barrier function of DNCB induced contact dermatitis hairless mice. So, this study was performed to research the effect of Insamyangyoung-tang on the TEWL with high dose steroid injected hairless mice. Method : Hairless mice were divided into 4 groups ; Control group, Group A, Group B and Group C. All groups were injected triamcinolone O.4mg for 10 times. Control group was medicated distilled water during the experimental period. Group A was medicated distilled water for 5 days before the $1^{st}$ injection day, and then medicated Insamyangyoung-tang extract during the experimental period. Group B was medicated Insamyangyoung-tang extract for 5 days before the $1^{st}$ injection day, and then medicated distilled water during the experimental period. Group C was medicated Insamyangyoung-tang extract for 5 days before the $1^{st}$ injection day, and then medicated Insamyangyoung-tang extract during the experimental period. TEWL of each group was measured for 5 times. After the $10^{th}$ injection, the tissue sample was made and the damage of epithelial cell was examined. Statistical significance was set at p<0.05 by using non parametric methods and repeated-anova.. Results : Group C showed significant effect on TEWL change of hairless mice evoked by triamcinolone injection. Group A and Group B also showed some effect, but there was no statistical significance.

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Fabrication and Characteristics of ultra power-saving Schottky barrier rectifier (초절전형 Schottky barrier rectifier의 제조 및 그 특성)

  • Kim, Jun-Sik;Choe, Yeong-Ho;Park, Geun-Yeong;Choe, Si-Yeong
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.39 no.4
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    • pp.35-40
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    • 2002
  • Ultra-power-saving SBR has been fabricated by using vanadium and molybdenum with low work function. Because reverse leakage current is increased in inverse proportion to work function, we implanted argon ion on the n-Si layer for decreasing leakage current. The dose and acceleration energy of the argon implantation in the silicon was 1$\times$10$^{14}$ ion/$\textrm{cm}^2$, 40 keV, respectively. The forward voltages drop of fabricated V-SBR and Mo-SBR were 0.25 V and 0.39 V at the same forward current density of 60 A/$\textrm{cm}^2$. As a result, it was found that the reverse leakage current of the fabricated V-SBR was reduced over 20$mutextrm{A}$ by the argon implantation in comparison with the no implanted V-SBR. Also, owing to argon implantation, the inferiority of characteristic of the SBR was not detected.

The preparation of skin analogue composition having the liquid crystalline structure and its cosmetic applications

  • Lee, Dong-Kyu;Jeong, Kwan-Young
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.2
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    • pp.215-224
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    • 2013
  • Recently, many cosmetic researchers have been focused on the development of high functional cosmetics including anti-wrinkle and whitening. In these studies, they couldn't afford to pay a deep attention to stable encapsulations for unstable materials and efficient drug deliveries for them. Particularly, in order to show a degree of instant effects as cosmetics, they can't also ignore moisturizing effect enough to satisfy customers just after applying and its maintenance by improving the function of skin barrier as well as above two effects. Therefore, skin analogue systems have attracted considerable attention in the view of structural and compositional similarity to intercellular membrane in stratum corneum. And, some models for skin analogue composition were developed to improve the function of skin barrier, stably encapsulate unstable materials such as retinol, vitamin B, C, E, etc., and control their skin penetration in order to show good effects as cosmetics. In this study, we suggest the new skin analogue model having the compositional similarity as well as conventional structural ones. Our skin analogue membrane(SAM) is mainly composed of ceramide/ cholesterol/phosphatidylcholin/fatty acids and its structural defects are compensated by including cholesterol amphiphile and controlling the ratio of ceramide/cholesterol. It was possible to confirm the formation of skin analogue membrane having highly-densed multilamella structure and compare them according to the change of each ratio with a polarized microscope, X-ray diffraction. More detaily, we observed their structures with a electron microscope(TEM). Finally, we dispersed them in excess of continuous water phase, observed the formation of maltese-cross liquid crystalline and measured the efficiency of drug deliveries and moisturizing effects.

Functional Assessment of Frequency of a Commercial Shampoo for Normal Canine Skin (개에서 피부세정제 적용빈도가 정상피부에 미치는 영향)

  • Yu, Jong-Won;Shin, Hee-Ju;Bae, Seulgi;Choi, Sungwon;Oh, Tae-Ho
    • Journal of Veterinary Clinics
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    • v.30 no.4
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    • pp.283-287
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    • 2013
  • Canine skin is a highly dynamic organ that is constantly adapted to changes in its environment. It provides structural, sensory, immunologic, and physiologic functions and contributes an essential barrier function against potential environmental insults. We assessed the changes of canine skin hydration, pH, and protein contents by noninvasive method according to the frequency of application with canine commercial shampoo. Canine commercial shampoo was applied topically every other day, 5 days, and 8 days on different sites, respectively in 8 dogs. Saline-applied site was as a control. Skin hydration was increased and skin surface pH was decreased significantly in canine commercial shampoo-applied site every other day (p < 0.05). Also, skin protein concentration measured by D-squame$^{(R)}$ tape stripping method was increased significantly in canine commercial shampoo-applied site every other day (p < 0.05). There were alterations on every 5 days and 8 days, but not significantly. These results may be recognized that the frequent use of canine commercial shampoo cause abnormalities of the skin barrier function and alteration of stratum corneum integrity/cohesion. Consequently it was suggested that bathing the dog with canine commercial shampoo was appropriate every 5 or 8 days.