• 제목/요약/키워드: blocking effect

검색결과 904건 처리시간 0.024초

산화아연 나노입자 유형이 카라기난 기반 복합 필름의 구조, 기계적 및 항균 특성에 미치는 영향 (Effect of zinc oxide nanoparticle types on the structural, mechanical and antibacterial properties of carrageenan-based composite films)

  • 신가영;김효린;박소윤;박미소;김찬형;허재영
    • 한국식품저장유통학회지
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    • 제31권1호
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    • pp.126-137
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    • 2024
  • 카라기난 기반 복합필름은 세 가지 다른 아연 염(zinc acetate, zinc chloride 및 zinc nitrate) 원료를 사용하여 합성한 ZnONPs를 카라기난에 첨가하여 solvent casting 방법으로 제작되었다. SEM 결과에 따르면, 사용된 아연 염의 종류에 따라 ZnONPs의 크기와 모양에 차이가 나타났지만, 모든 ZnONPs가 카라기난 복합필름 내에서 균일하게 분산되어 있는 것을 확인할 수 있었다. 카라기난 기반 복합필름(Car-ZnONPs)의 두께는 아연 염의 종류와 관계없이 순수 카라기난 필름에 비해 증가하였다. 파단 연신율(EB)은 증가하였고, 인장강도(TS)는 유의적으로 감소하였으며, 탄성 계수(EM)는 유의적 차이를 나타내지 않았다. 이를 통해 복합필름의 기계적 특성인 TS와 EB는 첨가된 나노입자의 크기와 첨가량에 영향을 받는다는 것을 확인하였다. 또한, 모든 종류의 Car-ZnONPs 복합필름은 E. coli O157:H7 및 L. monocytogenes 에 대해 강한 항균 활성을 나타냈으며, 특히 zinc chloride로 합성된 Car-ZnONPsZC 필름이 가장 우수한 항균 성능을 나타냈다. 이는 zinc chloride에서 합성된 나노입자가 다른 아연 염에 비해 더 많은 아연 이온을 방출하기 때문으로 판단된다. 아연 염의 종류가 ZnONPs의 항균 능력에 영향을 미치며, 이러한 영향은 염의 종류에 따라 변화하는 ZnONPs의 크기, 형태 및 아연 이온 방출 정도에서 기인한다. 평가된 복합필름 중 Car- ZnONPsZC가 가장 높은 자외선 차단 특성을 보였으며, 파단 연신율도 순수 카라기난 필름에 비해 유의미하게 증가하여, 포장된 식품의 안전성을 유지하고 유통기한을 연장하는 데 활성 포장 필름으로 사용될 수 있을 것으로 기대된다.

초고층 건축물 수직조닝별 연돌효과의 원인 및 해결 방안 분석 (Analysis of Causes of and Solutions to the Stack Effect by Vertical Zoning of High-rise Buildings)

  • 신상욱;류종우;정희웅;김대영
    • 한국건축시공학회지
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    • 제21권5호
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    • pp.483-493
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    • 2021
  • 도시 인구의 과밀화로 고층 건물에 대한 폭발적인 수요와 공급이 발생하였다. 고층 빌딩은 각 도시의 구심점으로 도시 이미지를 제고하는데 기여하고 있으나 연돌효과로 인해 승강기 문의 오작동, 외벽의 문과 창문 개폐의 어려움, 상층부로 확산하는 연기와 악취, 소음, 에너지 손실, 화재 및 오염물질의 급속한 확산 등 예기치 못한 다양한 문제를 야기하고 있다. 본 연구에서는 초고층 건축물을 수직조닝별로 구분하여 연돌효과의 원인과 해결방안을 분석하고 설계와 시공 방안으로 도출하였다. 외기를 차단하는 초기 계획과 정밀한 시공을 통한 기밀성 확보를 통해 저층부에서 유입되는 기류를 능동적으로 차단하여 건물의 내·외부 기밀성을 확보하는 방안을 모색하였다. 설비적 해결대책은 연돌효과로 인한 특정 현상을 줄이기 위한 대책이 될 수 있으나 이에 따른 2차 피해의 가능성이 높기 때문에 최소한으로 적용해야 한다. 따라서 본 연구는 연돌효과의 원인과 대책방안을 수직 조닝별로 설계적, 시공적 대책을 제시함으로써 체계적인 연돌효과 관리의 필요성을 역설하였다. 또한 본 연구가 설계 및 시공뿐만 아니라 건물 유지관리에도 도움이 되기를 기대한다.

Role of the Fas/Fas Ligand Death Receptor Pathway in Ginseng Saponin Metabolite-Induced Apoptosis in HepG2 Cells

  • Oh Seon-Hee;Yin Hu-Quan;Lee Byung-Hoon
    • Archives of Pharmacal Research
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    • 제27권4호
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    • pp.402-406
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    • 2004
  • This research team found in previous studies, that the ginseng saponin metabolite IH901 induces apoptosis in HepG2 cells via a mitochondrial-mediated pathway, which resulted in the activation of caspase-9 and subsequently of caspase-3 and -8. Based on these results, the involvement of the Fas/Fas ligand (FasL) death-receptor pathway, in IH901-induced apoptosis in HepG2 cells, was investigated. Levels of Fas and the Fas ligand (FasL) mRNA or protein were not increased by IH901, rather they were decreased significantly at 18 h post treatment. Soluble FasL (sFasL) was detectable by immunoprecipitation analysis En the medium of HepG2 cells treated with IH901. Increased levels of sFasL were inversely correlated with the levels of FasL. Preincubation of HepG2 cells with antagonistic anti-Fas antibody showed little protective effect, if any, on IH901-induced cell death. At a $30{\mu}M$ (24 and 48 h) and $40{\mu}M$ (24 h) concentration of IH901, the cytotoxic effect of IH901 was less then $50\%$, anti-Fas antibody prevented IH901-induced cell death. However, at a $60{\mu}M$ (24 and 48 h) and $40{\mu}M$ (48 h) concentration of IH901, cell death rates were about $80\%$ or more and most of the chemopreventive and chemotherapeutic effects of IH901 were manifested. Blocking the Fas receptor did not influence IH901-induced cell death. These results indicate that the Fas/FasL system is engaged, but not required for IH901-induced cell death, at pharmacologically significant concentrations.

토복령의 항염증 및 세포보호 효과에 미치는 영향 (Anti-Inflammatory Effects and Cytoprotective Effects of Smilacis Chinae Radix)

  • 이선구
    • 동의생리병리학회지
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    • 제23권1호
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    • pp.57-62
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    • 2009
  • 본 연구는 토복령의 항염증 및 세포보호 효과에 미치는 영향에 관한 것으로서 주요 내용은 다음과 같다. 본 실험에서는 세포독성, NO의 생성, PGE2, TNF-$\alpha$와 카탈라아제 농도, SOD, MAP kinase 등을 측정하였다. 본 실험의 결과 토복령 추출물은 세포 독성이 없었고 NO의 생성을 억제하며, 항염증과 세포보호 효과가 있었다. 그러나 이러한 효과에 대한 명확한 메커니즘에 대해서는 좀 더 연구가 필요하다는 내용이다.

Inhibitory Effect of the Ethanol Extract of a Rice Bran Mixture Comprising Angelica gigas, Cnidium officinale, Artemisia princeps, and Camellia sinensis on Brucella abortus Uptake by Professional and Nonprofessional Phagocytes

  • Hop, Huynh Tan;Arayan, Lauren Togonon;Reyes, Alisha Wehdnesday Bernardo;Huy, Tran Xuan Ngoc;Baek, Eun Jin;Min, WonGi;Lee, Hu Jang;Lee, Chun Hee;Rhee, Man Hee;Kim, Suk
    • Journal of Microbiology and Biotechnology
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    • 제27권10호
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    • pp.1885-1891
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    • 2017
  • In this study, we evaluated the inhibitory effect of a rice bran mixture extract (RBE) on Brucella abortus pathogenesis in professional (RAW 264.7) and nonprofessional (HeLa) phagocytes. We fermented the rice bran mixture and then extracted it with 50% ethanol followed by gas chromatography-mass spectrometry to identify the components in RBE. Our results clearly showed that RBE caused a significant reduction in the adherence of B. abortus in both cell lines. Furthermore, analysis of phagocytic signaling proteins by western blot assay revealed that RBE pretreatment resulted in inhibition of phosphorylation of JNK, ERK, and p38, leading to decline of internalization compared with the controls. Additionally, the intensity of F-actin observed by fluorescence microscopy and FACS was remarkably reduced in RBE-pretreated cells compared with control cells. However, the intracellular replication of B. abortus within phagocytes was not affected by RBE. Taken together, these findings suggest that the phagocytic receptor blocking and suppressive effects of RBE on the MAPK-linked phagocytic signaling pathway could negatively affect the invasion of B. abortus into phagocytes.

Unified solutions for piezoelectric bilayer cantilevers and solution modifications

  • Wang, Xianfeng;Shi, Zhifei
    • Smart Structures and Systems
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    • 제16권5호
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    • pp.759-780
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    • 2015
  • Based on the theory of piezoelasticity, the static performance of a piezoelectric bilayer cantilever fully covered with electrodes on the upper and lower surfaces is studied. Three models are considered, i.e., the sensor model, the driving displacement model and the blocking force model. By establishing suitable boundary conditions and proposing an appropriate Airy stress function, the exact solutions for piezoelectric bilayer cantilevers are obtained, and the effect of ambient thermal excitation is taken into account. Since the layer thicknesses and material parameters are distinguished in different layers, this paper gives unified solutions for composite piezoelectric bilayer cantilevers including piezoelectric bimorph and piezoelectric heterogeneous bimorph, etc. For some special cases, the simplifications of the present results are compared with other solutions given by other researches based on one-dimensional constitutive equations, and some amendments have been found. The present investigation shows: (1) for a PZT-4 piezoelectric bimorph, the amendments of tip deflections induced by an end shear force, an end moment or an external voltage are about 19.59%, 23.72% and 7.21%, respectively; (2) for a PZT-4-Al piezoelectric heterogeneous bimorph with constant layer thicknesses, the amendments of tip deflections induced by an end shear force, an end moment or an external voltage are 9.85%, 11.78% and 4.07%, respectively, and the amendments of the electrode charges induced by an end shear force or an end moment are both 1.04%; (3) for a PZT-4-Al piezoelectric heterogeneous bimorph with different layer thicknesses, the maximum amendment of tip deflection approaches 23.72%, and the maximum amendment of electrode charge approaches 31.09%. The present solutions can be used to optimize bilayer devices, and the Airy stress function can be used to study other piezoelectric cantilevers including multi-layered piezoelectric cantilevers under corresponding loads.

Typha orientalis inhibits inflammatory cytokine expression through suppression of ERK phosphorylation in HMC-1 cells

  • Choi, In-Young;Na, Ho-Jeong;Um, Jae-Young;Kim, Hyung-Min;Hong, Seung-Heon;Sim, Kuk-Jin;Song, Bong-Keun;Nam, Gi-Hye;Choung, Se-Young;Jeong, Hyun-Ja
    • Advances in Traditional Medicine
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    • 제10권1호
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    • pp.7-12
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    • 2010
  • Typha orientalis' stem (TOS) is traditionally used as an herbal medicine for difficulty in urination, galactophoritis purulenta, whooping cough, and allergic dermatitis. However, its effect in experimental models remains unknown. Here, we report the effect of TOS on the phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187-induced inflammatory cytokine production and extracellular signal-regulated kinase (ERK) activation in the human mast cell line, HMC-1. TOS inhibited PMA plus A23187-induced cytokines such as tumor necrosis factor-alpha (TNF-$\alpha$) and interleukin (IL)-6. Maximal inhibition rate of TNF-$\alpha$ and IL-6 production by TOS (1 mg/ml) was about 44.02%, and 45.20%, respectively (P < 0.05). In addition, TOS inhibited the expression of TNF-$\alpha$ and IL-6 mRNA under the same condition. Moreover, TOS partially blocked PMA plus A23187-induced ERK phosphorylation. These results suggested TOS could inhibit the cytokine production through blocking of ERK activity.

Naltrexone Inhibits Catecholamine Secretion Evoked by Nicotinic Receptor Stimulation in the Perfused Rat Adrenal Medulla

  • Yu, Byung-Sik;Min, Seon-Young;Seo, Yoo-Seok;Choi, Cheol-Hee;Lee, Eun-Hwa;Lim, Dong-Yoon
    • The Korean Journal of Physiology and Pharmacology
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    • 제9권4호
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    • pp.223-230
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    • 2005
  • The purpose of the present study was to examine the effect of naltrexone, an opioid antagonist, on secretion of catecholamines (CA) evoked by cholinergic nicotinic stimulation and membrane-depolarization from the isolated perfused rat adrenal gland and to establish the mechanism of its action. Naltrexone $(3{\times}10^{-6}M)$ perfused into an adrenal vein for 60 min produced time-dependent inhibition in CA secretory responses evoked by ACh $(5.32{\times}10^{-3}M)$ , high $K^+$ $(5.6{\times}10^{-2}M)$ , DMPP ($10^{-4}$ M) and McN-A-343 $(10^{-4}M)$ . Naltrexone itself did also fail to affect basal CA output. In adrenal glands loaded with naltrexone $(3{\times}10^{-6}M)$ , the CA secretory responses evoked by Bay-K-8644, an activator of L-type $Ca^{2+}$ channels and cyclopiazonic acid, an inhibitor of cytoplasmic $Ca^{2+}-ATPase$, were also inhibited. However, in the presence of met-enkephalin $(5{\times}10^{-6}M)$ , a well-known opioid agonist, the CA secretory responses evoked by ACh, high $K^+$, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid were also significantly inhibited. Collectively, these experimental results demonstrate that naltrexone inhibits greatly CA secretion evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors as well as that by membrane depolarization. It seems that this inhibitory effect of naltrexone does not involve opioid receptors, but might be mediated by blocking both the calcium influx into the rat adrenal medullary chromaffin cells and the uptake of $Ca^{2+}$ into the cytoplasmic calcium store, which are at least partly relevant to the direct interaction with the nicotinic receptor itself.

Effect of Visual and Somatosensory Information Inputs on Postural Sway in Patients With Stroke Using Tri-Axial Accelerometer Measurement

  • Chung, Jae-yeop
    • 한국전문물리치료학회지
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    • 제23권1호
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    • pp.87-93
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    • 2016
  • Background: Posture balance control is the ability to maintain the body's center of gravity in the minimal postural sway state on a supportive surface. This ability is obtained through a complicated process of sensing the movements of the human body through sensory organs and then integrating the information into the central nervous system and reacting to the musculoskeletal system and the support action of the musculoskeletal system. Motor function, including coordination, motor, and vision, vestibular sense, and sensory function, including proprioception, should act in an integrated way. However, more than half of stroke patients have motor, sensory, cognitive, and emotional disorders for a long time. Motor and sensory disorders cause the greatest difficulty in postural control among stroke patients. Objects: The purpose of this study is to determine the effect of visual and somatosensory information on postural sway in stroke patients and carrying out a kinematic analysis using a tri-axial accelerometer and a quantitative assessment. Methods: Thirty-four subjects posed four stance condition was accepted various sensory information for counterbalance. This experiment referred to the computerized dynamic posturography assessments and was redesigned four condition blocking visual and somatosensory information. To measure the postural sway of the subjects' trunk, a wireless tri-axial accelerometer was used by signal vector magnitude value. Ony-way measure analysis of variance was performed among four condition. Results: There were significant differences when somatosensory information input blocked (p<.05). Conclusion: The sensory significantly affecting the balance ability of stroke patients is somatosensory, and the amount of actual movement of the trunk could be objectively compared and analyzed through quantitative figures using a tri-axial accelerometer for balance ability.

마우스 대식세포에서 도기탕 (導氣湯) 메탄올 추출물의 항산화 및 항염증 효과 (Anti-oxidative and anti-inflammatory effect of Do-Ki-Tang methanol extract in mouse macrophage cells)

  • 김동완;윤현정;허준영;김태훈;조현진;박선동
    • 대한본초학회지
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    • 제25권4호
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    • pp.103-112
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    • 2010
  • Objective : The aim of this study was to determine whether methanol extract of Do-Ki-Tang (DKT) inhibit free radical generation and production of nitrite an index of NO, $PGE_2$, iNOS, COX-2 and pro-inflammatory cytokines such as TNF-${\alpha}$, IL-$1{\beta}$, IL-6 and MCP-1 in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Methods : Cytotoxic activity of extract on RAW 264.7 cells was measured using 5-(3-caroboxymeth-oxyphenyl)-2H-tetra-zolium inner salt (MTS) assay. The expression level of inflammatory response-related proteins was confirmed by western blot. The production of proinflammatory cytokines was measured by ELISA. Results : Our results indicated that DKT scavenged DPPH radical and nitric oxide in vitro. Moreover, DKT significantly inhibited the LPS-induced NO, $PGE_2$ production and iNOS, COX-2 expression accompanied by an attenuation of TNF-${\alpha}$, IL-$1{\beta}$, IL-6 and MCP-1 formation in macrophages. Furthermore, DKT treatment also blocked LPS-induced intracellular ROS production and the activation of NF-${\kappa}B$ and MAPKs. Conclusion : Our data suggest that the anti-inflammatory effect of DKT is mediated through down-modulation of pro-inflammatory mediators and cytokines by blocking the signaling pathways of NF-${\kappa}B$ and MAPKs. These inhibitory effects by DKT represent a potential therapeutic approach to the treatment of inflammatory diseases.