• International Journal of Automotive Technology
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• v.6 no.5
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• pp.491-499
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• 2005

There are different types of vehicle impacts recorded every year, resulting in many injuries and fatalities. The severity of these impacts depends on the aggressivety and incompatibility of vehicle-to-roadside hardware impacts. The aim of this paper is to investigate and to enhance crashworthiness in the case of full barrier impact using a new idea of crash improvement. Two different types of smart structures have been proposed to support the function of the existing vehicle. The work carried out in this paper includes developing and analyzing mathematical models of vehicle-to-barrier impact for the two types of smart structures. It is proven from analytical analysis that the mathematical models can be used in an effective way to give a quick insight of real life crashes. Moreover, it is shown that these models are valid and flexible, and can be useful in optimization studies.

• BMB Reports
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• v.52 no.2
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• pp.111-112
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• 2019

Although many studies have reported that the breakdown of the blood-brain barrier (BBB) represents one of the major pathological changes in aging, the mechanism underlying this process remains relatively unexplored. In this study, we described that acid sphingomyelinase (ASM) derived from endothelial cells plays a critical role in BBB disruption in aging. ASM levels were elevated in the brain endothelium and plasma of aged humans and mice, resulting in BBB leakage through an increase in caveolae-mediated transcytosis. Moreover, ASM caused damage to the caveolae-cytoskeleton via protein phosphatase 1-mediated ezrin/radixin/moesin dephosphorylation in primary mouse brain endothelial cells. Mice overexpressing brain endothelial cell-specific ASM exhibited acceleration of BBB impairment and neuronal dysfunction. However, genetic inhibition and endothelial specific knock-down of ASM in mice improved BBB disruption and neurocognitive impairment during aging. Results of this study revealed a novel role of ASM in the regulation of BBB integrity and neuronal function in aging, thus highlighting the potential of ASM as a new therapeutic target for anti-aging.

• The Journal of Korean Medicine
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• v.21 no.4
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• pp.193-203
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• 2000

Objectives : Hindered barrier function of vascular endothelium has been implicated in the initiation and progression of degenerative vascular diseases such as atherosclerosis. In this study, the effect of Sunghyangchungisan(SHCS) as a protectant against oxidant-induced destruction of endothelial barrier function was assessed. Methods : Toward this end, endothelial cells derived from the human umbilical vein were cultured as monolayers on permeable membrane filters. Endothelial permeability was monitored by measuring transendothelial electrical resistance and movement of low density lipoprotein (LDL) across the endothelial monolayer. Results : Along with increased movement of LDL, $H_2O_2$-induced increase in endothelial permeability was paralleled by a decrease in transendotheliaI electrical resistance. The effect of $H_2O_2$ was mimicked by phorbol 12-myristate 13-acetate (PMA), a potent activator of proteinkinase C. Calphostin-C, a protein kinase C inhibitor, effectively blocked the increase in endothelial permeability induced by $H_2O_2$ or PMA, indicating that activation of protein kinase C is associated with the $H_2O_2-induced$ permeability change. SHCS effectively protected the endothelial monolayer against $H_2O_2-induced$ increase in permeability, whereas, it did not affect PMA-induced change. Forskolin, a potent activator of adenylyl cyclase, antagonized $H_2O_2$ to increase endothelial permeability. In addition, in ${H_2O_2}-treated$ cens, intracenular cAMP concentration was significantly decreased, indicating that impaired cAMP production as well as activation of proteinkinase C is a mechanism underlying ${H_2O_2}>-induced$$H_2O_2$ with regard to its effect on intracellular cAMP content. However, SHCS itself did not affect resting cAMP concentration in endothelial cells. Conclusions : These results suggest that SHCS might operate as an effective protectant against oxidant-induced destruction of endothelial barrier function. The mechanism does not appear to involve direct interaction with protein kinase C- or cAMP-associated signaling mechanism.

• Preventive Nutrition and Food Science
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• v.20 no.1
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• pp.15-21
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• 2015

The skin plays a key role in protecting the body from the environment and from water loss. Cornified envelope (CE) and natural moisturizing factor (NMF) are considered as the primary regulators of skin hydration and barrier function. The CE prevents loss of water from the body and is formed by cross-linking of several proteins. Among these proteins, filaggrin is an important protein because NMF is produced by the degradation of filaggrin. Proteases, including matriptase and prostasin, stimulate the generation of filaggrin from profilaggrin and caspase-14 plays a role in the degradation of filaggrin. This study elucidated the effects of an ethanol extract of Boesenbergia pandurata (Roxb.) Schltr., known as fingerroot, and its active compound panduratin A on CE formation and filaggrin processing in HaCaT, human epidermal keratinocytes. B. pandurata extract (BPE) and panduratin A significantly stimulated not only CE formation but also the expression of CE proteins, such as loricrin, involucrin, and transglutaminase, which were associated with $PPAR{\alpha}$ expression. The mRNA and protein levels of filaggrin and filaggrin-related enzymes, such as matriptase, prostasin, and caspase-14 were also up-regulated by BPE and panduratin A treatment. These results suggest that BPE and panduratin A are potential nutraceuticals which can enhance skin hydration and barrier function based on their CE formation and filaggrin processing.

• Food Science of Animal Resources
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• v.37 no.6
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• pp.931-939
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• 2017

Alcoholic liver disease (ALD) is a complex multifaceted disease that involves oxidative stress and inflammation as the key mediators. Despite decades of intensive research, there are no FDA-approved therapies, and/or no effective cure is yet available. Probiotics have received increasing attention in the past few years due to their well-documented gastrointestinal health-promoting effects. Interestingly, emerging studies have suggested that certain probiotics may offer benefits beyond the gut. Lactobacillus fermentum LA12 has been previously demonstrated to play a role in inflammatory-related disease. However, the possible protective effect of L. fermentum LA12 on ALD still remain to be explored. Thus, the aim of this study was to evaluate the possible protective effect of L. fermentum LA12 on alcohol-induced gut barrier dysfunction and liver damage in a rat model of alcoholic steatohepatitis (ASH). Daily oral administration of L. fermentum LA12 in rat model of ASH for four weeks was shown to significantly reduced intestinal nitric oxide production and hyperpermeability. Moreover, small intestinal histological- and qRT-PCR analysis further revealed that L. fermentum LA12 treatment was capable of up-regulating the mRNA expression levels of tight junction proteins, thereby stimulating the restitution of barrier structure and function. Serum and hepatic analyses also revealed that the restoration of epithelial barrier function may prevent the leakage of endotoxin into the blood, subsequently improve liver function and hepatic steatosis in the L. fermentum LA12-treated rats. Altogether, results in this study suggest that L. fermentum LA12 may be used as a dietary adjunct for the prevention and treatment of ASH.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.20 no.1 s.32
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• pp.99-114
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• 2007

Objectives : Atopic dermatitis has a close relationship with damage of skin barrier function. To investigate the effects of Bangpungtongsungsan(BT) extract to the skin damage on mice model after atopic dermatitis elicitation, this study was done through forcing injury to mice's skin. Methods : The BALB/c mice were distributed into three groups: control(CON) group, atopic dermatitis(AD)-elicited group, Bangpungtongsungsan(BT)-treated group. AD-elicited and BT-treated group were caused AD according to the method of Christophers E., Mrowietz and Minehiro. The BT extract was administered for 48 hours to BT-treated group. We observed changes of external dermal formation, eosinophils in vasculature, lipid formation in stratum corneum, distribution of ceramide, distribution of capillary, $I{\kappa}B$ kinase(IKK) and induce nitric oxide synthase(iNOS) mRNA expression. We used the statistical methods of student t-test(p<0.05). Results : After dispensing BT extract into the AD-elicited group, the number of eosinophil as an atopic index in mice noticeably decreased and dermal injury decreased. Also the decrease of hyperplasia, degranulated mast cells, angiogenesis and substance P were shown. The lipid lamellae, lipid protect formation, were repaired and the distribution of ceramide which inhibit protein kinase C(PKC) activation increased, and the PKC caused inhibition of nuclear $factor(NF)-{\kappa}B$ activation. As a result of inhibition of $NF-{\kappa}B$ activation, iNOS production were inhibited and apoptotic cell were increased. Moreover the decrease of IKK and iNOS mRNA expression in BT-treated RAW 264.7 cell were noted. Conclusion : BT mitigated skin damage on mice model after atopic dermatitis elicitation through recovering skin barrier function and inhibiting nuclear $factor(NF)-{\kappa}B$ activation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.43 no.4
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• pp.329-335
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• 2017

We have studied on the keratinocytes differentiation and skin barrier function using Adenophorae radix (A. radix) root extract, which was known to contain triterpenoid, saponin and starch. A. radix root extracts showed the $PPAR{\alpha}$ expression level of Wy-14,643 $0.5-1.0{\mu}M$ in CV-1 cells. The cornified envelop formation (CE) of human keratinocyte cell line (HaCaT) and normal human keratinocyte (NHK) showed a statistically significant increased compared to the control. When HaCaT cells were treated with A. radix root extract, transglutaminase (TGase-1) was significantly increased. As a result of clinical study of the simple cosmetic formulation containing A. radix root extract for about 2 weeks, TEWL values were significantly decreased and water contents were increased. The ceramides, which were obtained from the inner forearm, were also significantly increased statistically. We suggest that the A. radix root extract can be used as a preventive and therapeutic agent for skin diseases such as dry skin and atopy.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.22 no.1
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• pp.27-39
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• 1996

Recently, in vitro stratum curneum model was a useful tool to evaluate the skin condition such as tranespidermal water loss, skin hydration and etc.. In this study to evaluate the alteration of SC with aging in hairless mouse, we measured TEWL using in vitro SC model, SC lipid, and outer corneocytes area. Although the total SC lipid was rich about 30% in 8 week old mouse compared with that of 82 week old mouse, the TEWL values were higher in the former than that of the latter. The outer corneocytes area was 559 $\pm$ 65 $mu extrm{m}$2 in 8 week old mouse and 755 $\pm$ 56 ${\mu}{\textrm}{m}$2 in 82 week old mouse. So the barrier function was reinforced with aging. This result suggested that the reinforced barrier function is one of the defense systems against the outer enviornment and the decreased skin function with aging.

• Applied Chemistry for Engineering
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• v.23 no.3
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• pp.289-292
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• 2012

Au electrodes modified with self-assembled monolayers (SAMs) were used to control the work function of source/drain electrodes in triethylsilylethynyl anthradithiophene (TES ADT)-based organic thin film transistors (OTFTs). By using benzothiol (BT) and pentafluorobenzothiol (PFBT) SAMs, the hole injection barrier between Au and the highest occupied molecular orbital (HOMO) of TES ADT was controlled. After a solvent annealing, TES ADT OTFTs with PFBT SAM-treated Au electrodes were found to exhibit high field-effect mobilities of $0.05\;cm^2/Vs$ and on/off current ratios of $10^6$.

• The Korean Journal of Ceramics
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• v.2 no.2
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• pp.95-101
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• 1996

Variations of the leakage current behaviors and interface potential barrier $({\Phi}_B)$ of rf-sputter deposited (Ba, Sr)$TiO_3$ (BST) thin films with thicknesses ranging from 20 nm to 150nm are investigated as a function of the thickness and bias voltages. The top and bottom electrodes are dc-sputter-deposited Pt films. ${\Phi}_B$ critically depends on the BST film deposition temperature, postannealing atmosphere and time after the annealing. The postannealing under $N_2$ atmosphere results in a high interface potential barrier height and low leakage current. Maintaining the BST capacitor in air for a long time reduces the ${\Phi}_B$ from about 2.4 eV to 1.6 eV due to the oxidation. ${\Phi}_B$ is not so dependent on the film thickness in this experimental range. The leakage conduction mechanism is very dependent on the BST film thickness; the 20 nm thick film shows tunneling current, 30 and 40 nm thick films show Shottky emission current.