• 제목/요약/키워드: barrier function

검색결과 593건 처리시간 0.035초

Probiotics의 작용기전 (Mechanisms of Action of Probiotics)

  • 고재성
    • Clinical and Experimental Pediatrics
    • /
    • 제48권7호
    • /
    • pp.691-695
    • /
    • 2005
  • There is scientific evidence that administration of probiotics is effective in the treatment of acute infectious diarrhea in children and the prevention of antibiotic associated diarrhea and nosocomial/community acquired diarrhea. Probiotics prevent relapse of recurrent pouchitis and decrease the initial onset of pouchitis in ulcerative colitis. Probiotic organisms suppress growth of pathogens as well as their epithelial attachment and/or invasion either directly by secreting antimicrobial substances or by stimulating host expression of protective molecules. Additionally, probiotics enhance mucosal barrier function and can stimulate host production of immunosuppressive molecules that downregulate inflammatory responses or allergic immune response. Mechanisms of action explain therapeutic effects and randomized controlled trials are warranted before recommendations for therapeutic or preventive use can be given.

The activation of PPAR-α and Wnt/β-catenin by Paeonia lactiflora root supercritical carbon dioxide extract

  • Kim, Bora
    • 한국응용과학기술학회지
    • /
    • 제36권4호
    • /
    • pp.1136-1142
    • /
    • 2019
  • The root of Paeonia lactiflora has been used in Chinese medicine. We conducted to check the comparative qualities of ethanol solvent extraction (PLE) and supercritical carbon dioxide extraction (PLS) of P. lactiflora root. PLE had higher antioxidant and polyphenol contents than PLS. But, PLS were significantly increased peroxisome proliferator-activated receptor (PPAR)-α. In addition, PLS inhibited the adipocyte differentiation of 3T3-L1 cells. When treated with the extract at a concentration of 100 ㎍/mL, the Wnt/β-catenin pathway reporter luciferase activity of HEK 293-TOP cells increased approximately by 3-folds compared to that of the untreated control group. These results indicate that P. lactiflora supercritical carbon dioxide extract may serve as a cosmeceutical for improving skin barrier function and the treatment of obesity.

고들빼기 추출물이 인지질막 Liposome의 안정성 및 유동성에 미치는 영향 (Effects of Godulbaegi Extracts on the Stability and Fluidity of Phospholipid Liposomal Membranes)

  • 배송자;노승배;정복미
    • 한국식품영양과학회지
    • /
    • 제27권3호
    • /
    • pp.508-517
    • /
    • 1998
  • We investigated the effects of godulbaegi extracts on the physiochemical properties of biological membranes as membrane stability and fluidity employing the phospholipid liposomal membrances as a biomembrane-mimetic system. The addition of the godulbaegi extracts to the phospholipid exterted great effects stagbilized the barrier function of the liposomal membranes in proportion to the concentration of the additive and significantly increased the membranes fluidity. The values of the fluorescence polarization of 1,6-diphenyl 1,3,5-hexatriene (DPH) decreased gradually as the temperature increased, and decreased abruptly near the phase transition temperature (Tm) of the liposome from gel to liquid crystalline state as usual. These results suggest that the activities of the godulbaegi extracts to enhance the stability and fluidity of the liposomal membranes have implication in their biological activities.

  • PDF

Enhanced hole injection by oxygen plasma treatment on Au electrode for bottom-contact pentacene organic thin-film transistors

  • Kim, Woong-Kwon;Hong, Ki-Hyon;Kim, Soo-Young;Lee, Jong-Lam
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
    • /
    • pp.74-77
    • /
    • 2006
  • Thin $AuO_x$ layer was formed by $O_2$ plasma treatment on Au electrode. The surface work function of plasma treatment showed higher by 0.5 eV than that of bare Au, reducing the hole injection barrier at the Au/pentacene interface. Using $O_2$ plasma-treated Au source-drain electrodes, the field-effect mobility of bottom-contact pentacene-OTFT was increased from 0.05 to 0.1 $cm^2/Vs$.

  • PDF

Improving performance of organic thin film transistor using an injection layer

  • Park, K.M.;Lee, C.H.;Hwang, D.H.
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
    • /
    • pp.1413-1415
    • /
    • 2005
  • The OTFT performance depends strongly on the interfacial properties between an organic semiconductor and ${\alpha}$ metal electrode. The contact resistance is critical to the current flow in the device. The contact resistance arises mainly from the Schottky barrier formation due to the work function difference between the semiconductor and electrodes. We doped pentacene/source-drain interfaces with $F_4TCNQ$ (2,3,5,6-Tetrafluoro-7,7,8,8-tetracyanoquinodimethane), resulting in p-doped region at the SD contacts, in order to solve this problem. We found that the mobility increased and the threshold voltage decreased.

  • PDF

The Activation of PPAR-α and Wnt/β-catenin by Luffa cylindrica Supercritical Carbon Dioxide Extract

  • Kim, Bora
    • Natural Product Sciences
    • /
    • 제25권4호
    • /
    • pp.341-347
    • /
    • 2019
  • Luffa cylindrica (LC) is a very fast-growing climber and its fruit have been considered as agricultural wastes. We conducted to check the comparative qualities of ethanol solvent extraction (LCE) and supercritical carbon dioxide extraction (LCS) of L. cylindrica fruit and seed. LCS had higher antioxidant and polyphenol contents than LCE. LCS were significantly increased peroxisome proliferator-activated receptor (PPAR)-a and involucrin expression as epidermal differentiation marker in 3D skin equivalent model. LCS also showed antimicrobial activity against Staphylococcus aureus, a causative bacteria in atopic dermatitis. In addition, LCS inhibited the adipocyte differentiation of 3T3-L1 cells. When treated with the extract at a concentration of 100 ㎍/mL, the Wnt/β-catenin pathway reporter luciferase activity of HEK 293-TOP cells was increased approximately by 2-folds compared to that of the untreated control group. These results indicate that L. cylindrica supercritical carbon dioxide extract may serve as a cosmeceutical for improving skin barrier function and the treatment of obesity.

AN ANALYSIS OF THE FACTORS AFFECTING THE HYDRAULIC CONDUCTIVITY AND SWELLING PRESSURE OF KYUNGJU CA-BENTONITE FOR USE AS A CLAY-BASED SEALING MATERIAL FOR A HIGH-LEVEL WASTE REPOSITORY

  • Cho, Won-Jin;Lee, Jae-Owan;Kwon, Sang-Ki
    • Nuclear Engineering and Technology
    • /
    • 제44권1호
    • /
    • pp.89-102
    • /
    • 2012
  • The buffer and backfill are important components of the engineered barrier system in a high-level waste repository, which should be constructed in a hard rock formation at a depth of several hundred meters below the ground surface. The primary function of the buffer and backfill is to seal the underground excavation as a preferred flow path for radionuclide migration from the deposited high-level waste. This study investigates the hydraulic conductivity and swelling pressure of Kyungju Ca-bentonite, which is the candidate material for the buffer and backfill in the Korean reference high-level waste disposal system. The factors that influence the hydraulic conductivity and swelling pressure of the buffer and backfill are analyzed. The factors considered are the dry density, the temperature, the sand content, the salinity and the organic carbon content. The possibility of deterioration in the sealing performance of the buffer and backfill is also assessed.

Materials and Systems for Noise Control : Categorization and Challenges

  • Bolton, J. Stuart
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2010년도 춘계학술대회 논문집
    • /
    • pp.44-44
    • /
    • 2010
  • In this presentation, noise control materials will be discussed from several points-of-view. First, materials will be categorized in terms of their intended function: i.e., as dissipative materials, as barriers, and as media intended to modify some aspect of the sound field. Within each category, example implementations will be described as will modeling procedures. In the context of barrier materials, recent developments in the area of metamaterials will be described briefly, and problems with some recently suggested approaches will be highlighted. Acoustical cloaking will be described as a method of modifying a sound field in such a way that a sensitive area is shielded from noise exposure; the practical difficulties of this approach will also be described. Finally, within each category of material and approach, a series of suggested research challenges will be described.

  • PDF

규칙화된 Fe-Al 계 금속간 화합물의 산화특성과 미끄럼 마모거동과의 관계에 대한 연구 (A Study on the Relationship between Oxidation and Sliding Wear Behavior of Ordered Fe-Al Intermetallic Alloys)

  • 김용석
    • 한국소성가공학회:학술대회논문집
    • /
    • 한국소성가공학회 1999년도 춘계학술대회논문집
    • /
    • pp.144-148
    • /
    • 1999
  • The relationship between oxidation and sliding wear behavior of Fe-28 at%. Al alloys with B2 ordered structure has been investigated. Sliding wear tests of the alloys have been carried out under various environmental conditions using a pin-on-disk wear tester. The wear rate of the ordered alloys in an oxygen atmoshpere was found to be much lower than in an oxygen atmosphere showed that Fe2O oxides formed on the wearing surface. The oxide layer prevented direct contact of the two mating materials and therefore improved wear resistance of the Fe-Al intermetallic alloy. It was found that the surface Al2O3 oxide layer which provides good oxidation resistance and improved mechanical properties broke down easily and didnot function properly as an oxidation barrier.

  • PDF

$Nb/A1_2O_3/Nb$ 조셉슨 접합의 임계전류밀도 제어 (Jc control of $Nb/A1_2O_3/Nb$ Josephson junction)

  • 김규태;홍현권;이규원
    • 한국초전도ㆍ저온공학회논문지
    • /
    • 제4권1호
    • /
    • pp.1-3
    • /
    • 2002
  • Single Josephson junctions, which are of cross type, of $50 ${\mu}{\textrm}{m}$ {\times} 50 ${\mu}{\textrm}{m}$$ were fabricated under several oxidation conditions to Investigate controllabilities of critical current density (Jc) with the standard KRISS processes. Considering that the self-field effect suppresses the observed critical current (Ice) at high Jc region, we could reasonably estimate Jc values from I-V observations. The dependence of the obtained Jc as a function of exposure, which is equal to pressure (P) times time (t), was well fitted to a curve of Jc ~ (Pt)-0.34. The maximum Jc value at the controllability margin was found to be 3 kA/cm$^2$with the current equipment set up.