• Title/Summary/Keyword: barrier function

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Photosensitive Barrier Rib Paste and Materials and Process

  • Park, Lee-Soon;Kim, Soon-Hak;Jang, Dong-Gyu;Kim, Duck-Gon;Hur, Young-June;Tawfik, Ayman
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.823-827
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    • 2005
  • Barrier ribs in the plasma display panel (PDP) function to maintain the discharge space between the glass plates as well as to prevent optical crosstalk. Patterning of barrier ribs is one of unique processes for making PDP. Barrier ribs could be formed by screen-printing, sand blasting, etching, and photolithographic process. In this work photosensitive barrier rib pastes were prepared by incorporating binder polymer, solvent, functional monomers photoinitiator, and barrier rib powder of which surface was treated with fumed silica particles. Studies on the function of materials for the barrier rib paste were undertaken. After optimization of paste formulation and photolithographic process, it was applied to the photosensitive barrier rib green sheet and was found that photolithographic patterning of barrier ribs could be formed with good resolution up to $110{\mu}m$ height and $60{\mu}m$ width after sintering.

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Measurement of Sound Transmission Loss in a Sound Barrier Filled with the Rice-Straw Particles by the Transfer Function and Laboratory Measurement Methods

  • Kang, Chun-Won;Jang, Eun-Suk;Jang, Sang-Sik;Kang, Ho-Yang
    • Journal of the Korean Wood Science and Technology
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    • v.46 no.4
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    • pp.338-345
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    • 2018
  • The sound insulation capacity of a barrier is indicated by its transmission loss. In this study, the sound transmission loss of a sound barrier filled with rice-straw particles was measured by the transfer function method and a laboratory measurement method. The results of the two measurements were compared. The transmission losses measured by the two methods were similar above a frequency of 500 Hz. The loss increased greatly upon the introduction of a plywood to the sound barrier. The results of this study are expected to be used to design sound barriers for roads.

Structure and Function of Tight Junctions in the Skin (피부에서의 치밀이음의 구조와 기능)

  • Song, Mee;Baek, Ji Hwoon
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.48 no.2
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    • pp.181-188
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    • 2022
  • The skin protects the body from excessive water loss and the invasion of harmful substances, such as chemicals and microbes. The stratum corneum, is recognized as a very important physical barrier. However, in recent years evidence emerged that tight junctions (TJ) might also play a crucial role in barrier function of the skin. In the present study, TJ proteins including transmembrane proteins and plaque proteins, skin permeability barrier function and skin diseases of TJ were reviewed.

Analysis of Schottky Barrier Height in Small Contacts Using a Thermionic-Field Emission Model

  • Jang, Moon-Gyu;Lee, Jung-Hwan
    • ETRI Journal
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    • v.24 no.6
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    • pp.455-461
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    • 2002
  • This paper reports on estimating the Schottky barrier height of small contacts using a thermionic-field emission model. Our results indicate that the logarithmic plot of the current as a function of bias voltage across the Schottky diode gives a linear relationship, while the plot as a function of the total applied voltage across a metal-silicon contact gives a parabolic relationship. The Schottky barrier height is extracted from the slope of the linear line resulting from the logarithmic plot of current versus bias voltage across the Schottky diode. The result reveals that the barrier height decreases from 0.6 eV to 0.49 eV when the thickness of the barrier metal is increased from 500 ${\AA}$ to 900 ${\AA}$. The extracted impurity concentration at the contact interface changes slightly with different Ti thicknesses with its maximum value at about $2.9{\times}10^{20}\;cm^{-3}$, which agrees well with the results from secondary ion mass spectroscopy (SIMS) measurements.

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Context-Dependent Regulation of Type17 Immunity by Microbiota at the Intestinal Barrier

  • Begum Akuzum;June-Yong Lee
    • IMMUNE NETWORK
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    • v.22 no.6
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    • pp.46.1-46.25
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    • 2022
  • T-helper-17 (Th17) cells and related IL-17-producing (type17) lymphocytes are abundant at the epithelial barrier. In response to bacterial and fungal infection, the signature cytokines IL-17A/F and IL-22 mediate the antimicrobial immune response and contribute to wound healing of injured tissues. Despite their protective function, type17 lymphocytes are also responsible for various chronic inflammatory disorders, including inflammatory bowel disease (IBD) and colitis associated cancer (CAC). A deeper understanding of type17 regulatory mechanisms could ultimately lead to the discovery of therapeutic strategies for the treatment of chronic inflammatory disorders and the prevention of cancer. In this review, we discuss the current understanding of the development and function of type17 immune cells at the intestinal barrier, focusing on the impact of microbiota-immune interactions on intestinal barrier homeostasis and disease etiology.

Bacillus subtilis Protects Porcine Intestinal Barrier from Deoxynivalenol via Improved Zonula Occludens-1 Expression

  • Gu, Min Jeong;Song, Sun Kwang;Park, Sung Moo;Lee, In Kyu;Yun, Cheol-Heui
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.4
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    • pp.580-586
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    • 2014
  • Intestinal epithelial cells (IECs) forming the barrier for the first-line of protection are interconnected by tight junction (TJ) proteins. TJ alteration results in impaired barrier function, which causes potentially excessive inflammation leading to intestinal disorders. It has been suggested that toll-like receptor (TLR) 2 ligands and some bacteria enhance epithelial barrier function in humans and mice. However, no such study has yet to be claimed in swine. The aim of the present study was to examine whether Bacillus subtilis could improve barrier integrity and protection against deoxynivalenol (DON)-induced barrier disruption in porcine intestinal epithelial cell line (IPEC-J2). We found that B. subtilis decreased permeability of TJ and improved the expression of zonula occludens (ZO)-1 and occludin during the process of forming TJ. In addition, ZO-1 expression of IPEC-J2 cells treated with B. subtilis was up-regulated against DON-induced damage. In conclusion, B. subtilis may have potential to enhance epithelial barrier function and to prevent the cells from DON-induced barrier dysfunction.

The study on the factors which improve skin barrier recovery (피부장벽회복에 영향을 미치는 인자에 관한 연구)

  • Cha, Jae-Hoon;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.39-45
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    • 2008
  • Objective : Skin barrier protects skin against harmful environment. Its function includes antimicrobial barrier as well as physical barrier. But there are few studies about the factors which improve skin barrier recovery after injury. The aim of this study is to investigate the factors which improve skin barrier recovery. Method : Nine hairless mice was anesthetized by inhalation and we tape stripped them. We used thermometer to know temperature one day ago, before anesthesia, before tape stripping, and after tape stripping. Vapometer was used to know transepidermal water loss before tape stripping, after tape stripping. And we used doppler flowmeter to measure blood flow before tape stripping, after tape stripping. Result : After analyzed data, we concluded that temperature was lower after anesthesia than before anesthesia and after tape stripping than before tape stripping. We could know that transepidermal water loss was lower after tape stripping than before tape stripping and more blood flowed after tape stripping. Conclusion : In our study, it was observed that temperature, transepidermal water loss, blood flow changed after tape stripping. But we thought lowered temperature was pathologic situation, more blood flow was to recover after injury. In traditional korean medicine, cold(寒) and imbalance of blood flow(血行) don't only make many skin diseases, but cold(寒) also obstructs blood flow. So we need to study how to warm cold(寒) and improve blood flow.

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Vitamin D Improves Intestinal Barrier Function in Cirrhosis Rats by Upregulating Heme Oxygenase-1 Expression

  • Wang, Peng-fei;Yao, Dan-hua;Hu, Yue-yu;Li, Yousheng
    • Biomolecules & Therapeutics
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    • v.27 no.2
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    • pp.222-230
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    • 2019
  • Intestinal barrier dysfunction always accompanies cirrhosis in patients with advanced liver disease and is an important contributor facilitating bacterial translocation (BT), which has been involved in the pathogenesis of cirrhosis and its complications. Several studies have demonstrated the protective effect of Vitamin D on intestinal barrier function. However, severe cholestasis leads to vitamin D depletion. This study was designed to test whether vitamin D therapy improves intestinal dysfunction in cirrhosis. Rats were subcutaneously injected with 50% sterile $CCl_4$ (a mixture of pure $CCl_4$ and olive oil, 0.3 mL/100 g) twice a week for 6 weeks. Next, $1,25(OH)_2D_3$ ($0.5{\mu}g/100g$) and the vehicle were administered simultaneously with $CCl_4$ to compare the extent of intestinal histologic damage, tight junction protein expression, intestinal barrier function, BT, intestinal proliferation, apoptosis, and enterocyte turnover. Intestinal heme oxygenase-1 (HO-1) expression and oxidative stress were also assessed. We found that vitamin D could maintain intestinal epithelial proliferation and turnover, inhibit intestinal epithelial apoptosis, alleviate structural damage, and prevent BT and intestinal barrier dysfunction. These were achieved partly through restoration of HO-1 and inhibition of oxidative stress. Taken together, our results suggest that vitamin D ameliorated intestinal epithelial turnover and improved the integrity and function of intestinal barrier in $CCl_4$-induced liver cirrhotic rats. HO-1 signaling activation was involved in these above beneficial effects.

Electrical and Physical Characteristics of Nickel Silicide using Rare-Earth Metals (희토류 금속을 이용한 니켈 실리사이드의 전기 및 물리적 특성)

  • Lee, Won-Jae;Kim, Do-Woo;Kim, Yong-Jin;Jung, Soon-Yen;Wang, Jin-Suk
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.1
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    • pp.29-34
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    • 2008
  • In this paper, we investigated electrical and physical characteristics of nickel silicide using rare-earth metals(Er, Yb, Tb, Dy), Incorporated Ytterbium into Ni-silicide is proposed to reduce work function of Ni-silicide for nickel silicided schottky barrier diode (Ni-silicided SBD). Nickel silicide makes ohmic-contact or low schottky barrier height with p-type silicon because of similar work function (${\phi}_M$) in comparison with p-type silicon. However, high schottky barrier height is formed between Ni-silicide and p-type substrate by depositing thin ytterbium layer prior to Ni deposition. Even though the ytterbium is deposited below nickel, ternary phase $Yb_xN_{1-x}iSi$ is formed at the top and inner region of Ni-silicide, which is believed to result in reduction of work function about 0.15 - 0.38 eV.

Barrier Function Method in Reliability Based Design Optimization (장애함수법에 의한 신뢰성기반 최적설계)

  • Lee, Tae-Hee;Choi, Woon-Yong;Kim, Hong-Sun
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1130-1135
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    • 2003
  • The need to increase the reliability of a structural system has been significantly brought in the procedure of real designs to consider, for instance, the material properties or geometric dimensions that reveal a random or incompletely known nature. Reliability based design optimization of a real system now becomes an emerging technique to achieve reliability, robustness and safety of these problems. Finite element analysis program and the reliability analysis program are necessary to evaluate the responses and the probabilities of failure of the system, respectively. Moreover, integration of these programs is required during the procedure of reliability based design optimization. It is well known that reliability based design optimization can often have so many local minima that it cannot converge to the specified probability of failure. To overcome this problem, barrier function method in reliability based design optimization is suggested. To illustrate the proposed formulation, reliability based design optimization of a bracket is performed. AMV and FORM are employed for reliability analysis and their optimization results are compared based on the accuracy and efficiency.

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