• 대한방사선기술학회지:방사선기술과학
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• 제33권4호
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• pp.363-367
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• 2010

본 연구의 목적은 X-선촬영장치의 1차방어벽두께 계산에 관한 쉬운 방법의 연구이다. X-선촬영장치에 대한 1차방어벽의 두께 계산을 위하여, 차폐물질은 콘크리트를 선택하였다. 방어벽의 구역들은 관리구역과 비관리구역으로 분류하였다. 두께의 계산은 NCRP 보고서 49와 51의 데이터를 사용하였다. 최대관전압 100과 150 kVp를 갖는 X-선촬영장치들에 대하여, 콘크리트 두께들은 거리의 함수로서 계산되었다. 계산된 데이터로부터, 식 (3), (4), (5), 그리고 (6)은 지수감소함수의 정합을 수행하여 얻었다. 본 연구에서 얻어진 수식들로부터, 1차방어벽의 두께는 근사적으로 계산할 수 있다.

• BMB Reports
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• 제41권5호
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• pp.345-352
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• 2008

The cerebral microvessels possess barrier characteristics which are tightly sealed excluding many toxic substances and protecting neural tissues. The specialized blood-neural barriers as well as the cerebral microvascular barrier are recognized in the retina, inner ear, spinal cord, and cerebrospinal fluid. Microvascular endothelial cells in the brain closely interact with other components such as astrocytes, pericytes, perivascular microglia and neurons to form functional 'neurovascular unit'. Communication between endothelial cells and other surrounding cells enhances the barrier functions, consequently resulting in maintenance and elaboration of proper brain homeostasis. Furthermore, the disruption of the neurovascular unit is closely involved in cerebrovascular disorders. In this review, we focus on the location and function of these various blood-neural barriers, and the importance of the cell-to-cell communication for development and maintenance of the barrier integrity at the neurovascular unit. We also demonstrate the close relation between the alteration of the blood-neural barriers and cerebrovascular disorders.

• Biomolecules & Therapeutics
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• 제23권3호
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• pp.207-217
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• 2015

Skin is the first line of defense for protecting our bodies against external perturbations, including ultraviolet (UV) irradiation, mechanical/chemical stress, and bacterial infection. Nutrition is one of many factors required for the maintenance of overall skin health. An impaired nutritional status alters the structural integrity and biological function of skin, resulting in an abnormal skin barrier. In particular, the importance of micronutrients (such as certain vitamins and minerals) for skin health has been highlighted in cell culture, animal, and clinical studies. These micronutrients are employed not only as active compounds in therapeutic agents for treating certain skin diseases, but also as ingredients in cosmetic products. Here, the author describes the barrier function of the skin and the general nutritional requirements for skin health. The goal of this review is to discuss the potential roles and current knowledge of selected micronutrients in skin health and function.

• 한국재료학회지
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• 제21권2호
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• pp.95-99
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• 2011

The microstructure and Cu diffusion barrier property of Ta-Si-N films for various Si and N compositions were studied. Ta-Si-N films of a wide range of compositions (Si: 0~30 at.%, N: 0~55 at.%) were deposited by DC magnetron reactive sputtering of Ta and Si targets. Deposition rates of Ta and Si films as a function of DC target current density for various $N_2/(Ar+N_2)$ flow rate ratios were investigated. The composition of Ta-Si-N films was examined by wavelength dispersive spectroscopy (WDS). The variation of the microstructure of Ta-Si-N films with Si and N composition was examined by X-ray diffraction (XRD). The degree of crystallinity of Ta-Si-N films decreased with increasing Si and N composition. The Cu diffusion barrier property of Ta-Si-N films with more than sixty compositions was investigated. The Cu(100 nm)/Ta-Si-N(30 nm)/Si structure was used to investigate the Cu diffusion barrier property of Ta-Si-N films. The microstructure of all Cu/Ta-Si-N/Si structures after heat treatment for 1 hour at various temperatures was examined by XRD. A contour map that shows the diffusion barrier failure temperature for Cu as a function of Si and N composition was completed. At Si compositions ranging from 0 to 15 at.%, the Cu diffusion barrier property was best when the composition ratio of Ta + Si and N was almost identical.

• Biomolecules & Therapeutics
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• 제29권2호
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• pp.175-183
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• 2021

The mitogen-activated protein kinase (MAPK) pathway controls intestinal epithelial barrier permeability by regulating tight junctions (TJs) and epithelial cells damage. Heme oxygenase-1 (HO-1) and carbon monoxide (CO) protect the intestinal epithelial barrier function, but the molecular mechanism is not yet clarified. MAPK activation and barrier permeability were studied using monolayers of Caco-2 cells treated with tissue necrosis factor α (TNF-α) transfected with FUGW-HO-1 or pLKO.1-sh-HO-1 plasmid. Intestinal mucosal barrier permeability and MAPK activation were also investigated using carbon tetrachloride (CCl4) administration with CoPP (a HO-1 inducer), ZnPP (a HO-1 inhibitor), CO releasing molecule 2 (CORM-2), or inactived-CORM-2-treated wild-type mice and mice with HO-1 deficiency in intestinal epithelial cells. TNF-α increased epithelial TJ disruption and cleaved caspase-3 expression, induced ERK, p38, and JNK phosphorylation. In addition, HO-1 blocked TNF-α-induced increase in epithelial TJs disruption, cleaved caspase-3 expression, as well as ERK, p38, and JNK phosphorylation in an HO-1-dependent manner. CoPP and CORM-2 directly ameliorated intestinal mucosal injury, attenuated TJ disruption and cleaved caspase-3 expression, and inhibited epithelial ERK, p38, and JNK phosphorylation after chronic CCl4 injection. Conversely, ZnPP completely reversed these effects. Furthermore, mice with intestinal epithelial HO-1 deficient exhibited a robust increase in mucosal TJs disruption, cleaved caspase-3 expression, and MAPKs activation as compared to the control group mice. These data demonstrated that HO-1-dependent MAPK signaling inhibition preserves the intestinal mucosal barrier integrity by abrogating TJ dysregulation and epithelial cell damage. The differential targeting of gut HO-1-MAPK axis leads to improved intestinal disease therapy.

• 대한화장품학회지
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• 제49권4호
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• pp.323-330
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• 2023

피부의 장벽 구조는 표피의 각질 형성세포의 분화과정에 의해서 생성된다. 이 구조는 케라틴 단백질로 구성되는 각질세포와 그 사이를 채우고 있는 세포간 지질로 구성된다. 이때 표피의 기저층의 세포의 막을 이루던 인지질 등의 성분은 분해되어 없어지고, 세라마이드 등이 성분이 신규로 합성되어 각질층의 세포간 지질을 구성한다. 본 연구에서는 피부 장벽의 세포간 지질 구조의 패킹과 장벽기능에 진세노사이드 Rg3성분이 미치는 영향을 확인하였다. 이를 위해 3D피부 세포의 분화과정에 Rg3성분을 처리하였다. 3D피부를 대상으로 FT-IR 및 TEWL를 분석한 결과, 각질 세포간 지질의 orthorhombic패킹이 강화되고 장벽기능이 강화되는 것을 확인하였다. 또한 HaCaT세포에 Rg3를 처리한 경우, 긴 체인 길이의 지질을 합성하는 EVOL1 및 EVOL4의 발현 증가와 짧은 길이의 세라마이드의 합성을 당하는 CERS6의 감소 그리고 피토스핑고신을 사용하는 세라마이드를 분해시키는 ACER6의 증가를 검출하였다. 이를 통해 Rg3가 표피 분화 과정 중 지질의 합성에 영향을 주어 장벽 기능 변화를 가져올 가능성을 제시하였다.

• 한국해양생명과학회지
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• 제6권2호
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• pp.58-65
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• 2021

노화가 진행될수록 활성산소종으로 인하여 피부 보습은 떨어지고 피부 장벽은 붕괴되어 피부가 손상된다. 본 연구에서는 인천 동막 해변에 서식하는 염생식물인 갯끈풀(Spartina anglica; SAE)과 갯메꽃(Calystegia soldanella; CSE)을 70% 에탄올(EtOH)로 추출하여 피부 보습 및 피부 장벽 기능 강화에 대한 효능을 평가하였다. 이 추출물들에 대한 피부 각질형성세포(HaCaT cell)에서 세포독성을 WST-8 assay를 이용하여, 세포 생존율이 90% 이상을 보이는 농도를 선별하여 추가 실험을 진행하였다. ABTS 라디칼 소거능을 통해 항산화 효과를 확인한 결과, SAE와 CSE는 높은 라디칼 소거능을 보였다. 피부 보습과 관련된 인자들인 filaggrin (FGL), aquaporin 3(AQP3), hyaluronan synthase 2 (HAS2)과 피부 장벽 기능과 연관 있는 transglutaminase 1 (TGM1)과 involucrin (INV)의 유전자 수준에서의 발현 변화를 측정한 결과, SAE에 의해 AQP3, HAS2, TGM1의 발현이 증가하였으나, CSE는 변화가 없는 것을 확인할 수 있었다. SAE에 의한 세포 내 신호전달 경로를 확인하기 위해 western blot 분석을 수행하였다. Extracellular signal regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 mitogen activated protein kinase의 활성이 SAE에 의하여 상향 조절되었음을 확인하였다. 이러한 결과는 갯끈풀 추출물이 피부 보습 및 피부 장벽 기능 강화를 위한 화장품의 기능성 소재로 사용될 수 있음을 시사한다.

• 대한본초학회지
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• 제38권3호
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• pp.19-26
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• 2023

Objectives : Agrimoniae Herba is a herbal medicine widely distributed in Asia and contains flavonoids including catechin, quercitrin, rutin, hyperoside, and quercetin. This study aimed to investigate the anti-oxidant activity and skin barrier function of different solvent fractions (Hexane; methylene chloride, MC; ethyl acetate, EA; n-butanol, Bu; Water) obtained from Agrimoniae Herba. Methods : Anti-oxidant activity of different solvent fractions obtained from Agrimoniae Herba was investigated through total polyphenol contents, total flavonoid contents, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity measurements. Then, filament aggregating protein (Filaggrin), Type I collagen, ceramide synthase (CERS) 3, and CERS4 were analyzed to evaluate the skin barrier strengthening effect of different solvent fractions obtained from Agrimoniae Herba on UVB-stimulated HaCaT cells. Results : As a result of measuring total polyphenol contents, total flavonoid contents, DPPH free radical scavenging activity, and ABTS radical scavenging activity, antioxidant activity was found to be excellent in the order of EA > Bu > MC > Hexane > Water. As a result of measuring mRNA gene expression of Type I collagen, Filaggrin, CERS3, and CERS4 after UVB-stimulated was applied to HaCaT cells treated with different solvent fractions obtained from Agrimoniae Herba, it was found to increase significantly in the Bu-treated group. Conclusion : Our findings show that the Bu sample obtained from Agrimoniae Herba has excellent anti-oxidant ability, which increases Type I collagen, Filaggrin, and ceramide synthetase in UVB-stimulated HaCaT cells to control the skin barrier improvement effect.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
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• pp.21-22
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• 2003

4 types rubber related geosynthetics were manufactured to examine the performance to for applications to the civil and geotechnical fields, especially to the road construction. Reinforcement and water barrier function of these geosynthetics were interpreted as the important properties. Fiber glass mat based and geogrid based geosynthetics showed the excellent mechanical properties as. Also elastomeric bitumen based geosynthetic showed the highest permittivity. From this, it i s thought that this geosynthetic is suitable for water barrier under specific load condition.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1252-1254
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• 2005

Recently, PDP barrier ribs require the formation of complex structure so that they are usually formed by etching method. For producing the fine ribs structure, during the etching process the metal ions of matrix (glass) of barrier materials should be understood on the etching mechanism with etching condition. We analyzed the quantity of Pb, Si, and B ions from the etch solution as a function of etching time.