• Title/Summary/Keyword: Barrier factor

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The Change of Taurine Transport in Variable Stress States through the Inner Blood-Retinal Barrier using In Vitro Model

  • Kang, Young-Sook;Lee, Na-Young;Chung, Yeon-Yee
    • Biomolecules & Therapeutics
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    • v.17 no.2
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    • pp.175-180
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    • 2009
  • Taurine is the most abundant free amino acid in the retina and transported into retina via taurine transporter (TauT) at the inner blood-retinal barrier (iBRB). In the present study, we investigated whether the taurine transport at the iBRB is regulated by oxidative stress or disease-like state in a conditionally immortalized rat retinal capillary endothelial cell line (TR-iBRB) used as an in vitro model of iBRB. First, [$^3H$]taurine uptake and efflux by TR-iBRB were regulated in the presence of extracellular $Ca^{2+}$. [$^3H$]Taurine uptake was inhibited and efflux was enhanced under $Ca^{2+}$ free condition in the cells. In addition, oxidative stress inducing agents such as tumor necrosis factor-$\alpha$ (TNF-$\alpha$), lipopolysaccharide (LPS), diethyl maleate (DEM) and glutamate increased [$^3H$]taurine uptake and decreased [$^3H$]taurine efflux in TR-iBRB cells. Whereas, 3-morpholinosydnonimine (SIN-1), which is known to NO donor decreased [$^3H$]taurine uptake. Lastly, TR-iBRB cells exposed to high glucose (25 mM) medium and the [$^3H$]taurine uptake was reduced about 20% at the condition. Also, [$^3H$]taurine uptake was decreased by cytochalasin B, which is known to glucose transport inhibitor. In conclusion, taurine transport in TR-iBRB cells is regulated diversely at extracellular $Ca^{2+}$, oxidative stress and hyperglycemic condition. It suggested that taurine would play a role as a retinal protector in diverse disease states.

Effects of Salviae Miltiorrhizae Radix on Blood-Brain Barrier Impairment of ICH-Induced Rats (단삼(丹蔘)이 뇌조직출혈 흰쥐의 혈액뇌관문 손상에 미치는 영향)

  • Park, Chang-Hoon;Kim, Youn-Sub
    • The Korea Journal of Herbology
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    • v.29 no.1
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    • pp.19-26
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    • 2014
  • Objectives : This study was performed in order to evaluate the effects of Salviae Miltiorrhizae Radix (SMR) water extract against the cerebral hemorrhage and the blood-brain barrier (BBB) impairment in the intracerebral hemorrhage (ICH). Method : ICH was induced by the stereotaxic intrastriatal injection of bacterial collagenase type IV in Sprague-Dawley rats. SMR was orally given three times every 20 hours during 3 days after the ICH induction. Hematoma volume, water content of brain tissue and volume of evans blue leakage were examined. Myeloperoxidase (MPO) positive neutrophils and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) were observed with immunofluorescence labeling and confocal microscope. Results : SMR significantly reduced the hematoma volume of the ICH-induced rat brain. SMR significantly reduced the water content of brain tissue of the ICH-induced rat brain. SMR reduced the percentage of the evans blue leakage around the hematoma on the caudate putamen compared to the ICH group, especially on the cerebral cortex. SMR significantly reduced the volume of the evans blue leakage level in the peri-hematoma regions of the ICH-induced rat brain. SMR significantly reduced MPO positive neutrophils in the peri-hematoma regions of the ICH-induced rat brain. SMR reduced the TNF-${\alpha}$ expression in peri-hematoma regions of the ICH-induced rat brain. TNF-${\alpha}$ immuno-labeled cells were coincided with MPO immuno-labeled neutrophils in peri-hematoma regions of the ICH-induced rat brain. Conclusion : These results suggest that SMR plays a protective role against the blood-brain barrier impairment in the ICH through suppression of inflammation in the rat brain tissues.

Factors Affecting Practice of COVID-19 Infection Preventive Behaviors in University Students: The Use of the Extended Health Belief Model (HBM) and Theory of Planned Behavior (TPB) (대학생의 코로나19 감염예방행위에 영향을 미치는 요인: 확장된 건강신념모델과 계획된 행위이론의 적용)

  • Na Yeong Seok;Chi Yang Yoon;Mi Suk Lee;Mi Yang Jeon
    • Journal of the Korean Society of School Health
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    • v.36 no.1
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    • pp.9-19
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    • 2023
  • Purpose: The purpose of the study was to identify the factors affecting the practice of COVID-19 infection preventive behaviors in university students focusing on the extended health beliefs model (HBM) and the theory of planned behavior (TPB). Methods: Data was collected from November 1, 2021 to November 30, 2021. The participants were 180 university students at 3 universities. The data was analyzed through the independent t-test, one-way ANOVA, Scheffé test, Pearson's correlation coefficient, and multiple regression by using SPSS/WIN 24.0. Results: In the first stage of hierarchical regression analysis, it was shown that perceived barrier and self-efficacy, among the HBM variables, were significant factors, explaining 18.4% of the infection preventive behaviors (F=7.73, p<.001). In the 2nd stage, it was shown that self-efficacy, among the TPB variables, was a significant factor, explaining 15.3% of the infection preventive behaviors (F=11.80, p<.001). In the 3rd stage, it was shown that perceived barrier and self-efficacy, among the HBM and TPB variables, were significant factors, explaining 18.5% of the infection preventive behaviors (F=6.08, p<.001). Conclusion: When an effective infection preventive behavior program is developed and provided for students to improve their self-efficacy and reduce perceived barrier based on the results, it will contribute to the improvement of infection prevention behaviors among university students.

Structuyal and physical properties of thin copper films deposited on porous silicon (다공성 실리콘위에 증착된 Cu 박막의 구조적 물리적 특성)

  • 홍광표;권덕렬;박현아;이종무
    • Journal of the Korean Vacuum Society
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    • v.12 no.2
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    • pp.123-129
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    • 2003
  • Thin transparent Cu films in the thickness range of 10 ~ 40 nm are deposited by rf-magnetron sputtering on porous silicon (PS) anodized on p-type silicon in dark. Microstructural features of the Cu films are investigated using SEM, AFM and XRD techniques. The RMS roughness of the Cu films is found to be around 1.47 nm and the grain growth is columnar with a (111) preferred orientation and follows the Volmer-Weber mode. The photoluminescence studies showed that a broad luminiscence peak of PS near the blue-green region gets blue shifted (~0.05 eV) with a small reduction in intensity and therefore, Cu-related PL quenching is absent. The FTIR absorption spectra on the PS/Cu structure revealed no major change of the native PS peaks but only a reduction in the relative intensity. The I-V characteristic curves further establish the Schottky nature of the diode with an ideality factor of 2.77 and a barrier height of 0.678 eV. An electroluminiscence (EL) signal of small intensity could be detected for the above diode.

The Changes of P-glycoprotein Activity by Interferon-γ and Tumor Necrosis Factor-α in Primary and Immortalized Human Brain Microvascular Endothelial Cells

  • Lee, Na-Young;Rieckmann, Peter;Kang, Young-Sook
    • Biomolecules & Therapeutics
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    • v.20 no.3
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    • pp.293-298
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    • 2012
  • The purpose of this study was to investigate the modification of expression and functionality of the drug transporter P-glycoprotein (P-gp) by tumor necrosis factor-alpha (TNF-${\alpha}$) and interferon-gamma (IFN-${\gamma}$) at the blood-brain barrier (BBB). We used immortalized human brain microvessel endothelial cells (iHBMEC) and primary human brain microvessel endothelial cells (pHBMEC) as in vitro BBB model. To investigate the change of p-gp expression, we carried out real time PCR analysis and Western blotting. To test the change of p-gp activity, we performed rhodamin123 (Rh123) accumulation study in the cells. In results of real time PCR analysis, the P-gp mRNA expression was increased by TNF-${\alpha}$ or IFN-${\gamma}$ treatment for 24 hr in both cell types. However, 48 hr treatment of TNF-${\alpha}$ or IFN-${\gamma}$ did not affect P-gp mRNA expression. In addition, co-treatment of TNF-${\alpha}$ and IFN-${\gamma}$ markedly increased the P-gp mRNA expression in both cells. TNF-${\alpha}$ or IFN-${\gamma}$ did not influence P-gp protein expression whatever the concentration of cytokines or duration of treatment in both cells. However, P-gp expression was increased after treatments of both cytokines together in iHBMEC cells only compared with untreated control. Furthermore, in both cell lines, TNF-${\alpha}$ or IFN-${\gamma}$ induced significant decrease of P-gp activity for 24 hr treatment. And, both cytokines combination treatment also decreased significantly P-gp activity. These results suggest that P-gp expression and function at the BBB is modulated by TNF-${\alpha}$ or/and IFN-${\gamma}$. Therefore, the distribution of P-gp depending drugs in the central nervous system can be modulated by neurological inflammatory diseases.

Effects of housing renovation cost for the disabled on their housing satisfaction (장애인 주택개조 비용이 거주후 만족도에 미치는 영향)

  • Lee, So-Young;Kim, Mi-Jung
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2011.04a
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    • pp.172-175
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    • 2011
  • Financial supports for housing for the disabled is limited since a certain amount of budget needs to be distributed for a number of disabled families. Therefore, it is important to fund renovation for the disabled effectively and properly. Financial and administrative supports for the renovation which intended to improve housing conditions in terms of accessibility (barrier free) and comfort needs to be implemented with larger outcome and smaller budget. The purpose of this study was to investigate various factor such as renovation cost and renovation elements, influence satisfaction of residents with disabilities. Participants of this study are limited to the recipients of financial supports for housing renovation and refurbishment from City of Seoul and Ministry of Heal and Welfare. A total of 155 cases were analyzed using post occupancy survey and analysis of project cost data. Overall, more cost were used for modification for housing condition improvement than the cost for removal of architectural barriers. Renovation cost differences were not apparent among the type and extent of an individual's disabilities. Instead existing housing type and physical condition for the housing affects cost for renovation more significantly. Overall the renovation cost is positively related to resident's satisfaction using regression analysis.

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The Electrical Properties of GaN Individual Nanorod Devices by Wet-etching of the Nanorod Surface and Annealing Treatment (표면 습식 식각 및 열처리에 따른 GaN 단일 나노로드 소자의 전기적 특성변화)

  • Ji, Hyun-Jin;Choi, Jae-Wan;Kim, Gyu-Tae
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.2
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    • pp.152-155
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    • 2011
  • Even though nano-scale materials were very advantageous for various applications, there are still problems to be solved such as the stabilization of surface state and realization of low contact resistances between a semiconducting nanowire and electrodes in nano-electronics. It is well known that the effects of contacts barrier between nano-channel and metal electrodes were dominant in carrier transportation in individual nano-electronics. In this report, it was investigated the electrical properties of GaN nanorod devices after chemical etching and rapid thermal annealing for making good contacts. After KOH wet-etching of the contact area the devices showed better electrical performance compared with non-treated GaN individual devices but still didn't have linear voltage-current characteristics. The shape of voltage-current properties of GaN devices were improved remarkably after rapid thermal annealing as showing Ohmic behaviors with further bigger conductivities. Even though chemical etching of the nanorod surfaces could cause scattering of carriers, in here it was shown that the most important and dominant factor in carrier transport of nano-electronics was realization of low contact barrier between nano-channel and metal electrodes surely.

Performances of a-Si:H thin-film solar cells with buffer layers at TCO/p a-SiC:H interface (CO/p a-SiC:H 계면의 버퍼층에 따른 비정질 실리콘 박막태양전지 동작특성)

  • Lee, Ji-Eun;Jang, Ji-Hun;Jung, Jin-Won;Park, Sang-Hyun;Jo, Jun-Sik;Yoon, Kyung-Hoon;Song, Jin-Soo;Kim, Dong-Hwan;Lee, Jeong-Chul
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.32-32
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    • 2009
  • 실리콘 박막 태양전지에서 전면 투명전도막(TCO)은 태양전지의 전기, 광학적 특성을 결정하는 중요한 기능을 한다. ZnO:Al TCO는 기존에 사용되던 $SnO_2:F$와는 비정질 실리콘(a-Si:H) 박막 태양전지의 윈도우 층으로 사용되는 p a-SiC:H와의 일함수(work function) 차이로 인해 접촉전위(contact barrier)를 형성하게 되며 이로 인해 태양전지의 충진율(fill factor)이 $SnO_2:F$에 비해 감소하는 단점을 보인다. 본 연구에서는 ZnO:Al/p a-SiC:H 계면의 접촉전위 발생원인 및 태양전지 충진율 감소현상에 관한 정확한 원인규명을 위해 다양한 특성을 갖는 버퍼층을 삽입하여 계면특성 및 태양전지의 동작특성을 분석하고자 한다.

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Applying the Health Belief Model to college students' health behavior

  • Kim, Hak-Seon;Ahn, Joo;No, Jae-Kyung
    • Nutrition Research and Practice
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    • v.6 no.6
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    • pp.551-558
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    • 2012
  • The purpose of this research was to investigate how university students' nutrition beliefs influence their health behavioral intention. This study used an online survey engine (Qulatrics.com) to collect data from college students. Out of 253 questionnaires collected, 251 questionnaires (99.2%) were used for the statistical analysis. Confirmatory Factor Analysis (CFA) revealed that six dimensions, "Nutrition Confidence," "Susceptibility," "Severity," "Barrier," "Benefit," "Behavioral Intention to Eat Healthy Food," and "Behavioral Intention to do Physical Activity," had construct validity; Cronbach's alpha coefficient and composite reliabilities were tested for item reliability. The results validate that objective nutrition knowledge was a good predictor of college students' nutrition confidence. The results also clearly showed that two direct measures were significant predictors of behavioral intentions as hypothesized. Perceived benefit of eating healthy food and perceived barrier for eat healthy food to had significant effects on Behavioral Intentions and was a valid measurement to use to determine Behavioral Intentions. These findings can enhance the extant literature on the universal applicability of the model and serve as useful references for further investigations of the validity of the model within other health care or foodservice settings and for other health behavioral categories.

Study on the pn Junction Device Using the POCl3 Precursor (POCl3를 사용한 pn접합 소자에 관한 연구)

  • Oh, Teresa
    • Journal of the Korean Vacuum Society
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    • v.19 no.5
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    • pp.391-396
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    • 2010
  • The pn junction for solar cell was prepared on p-type Si wafer by the furnace using the $POCl_3$ and oxygen mixed precursor to research the characteristic of interface at pn junction. The sheet resistance was decreased in accordance with the increasing the diffusion process time for n-type doping on p-type Si wafer. The electron affinity at the interface in the pn junction was decreased with increasing the amount of n-type doping and the sheet resistance also decreased. Consequently, the drift current due to the generation of EHP increased because of low potential barrier. The efficiency and fill factor were increased at the solar cell with increasing the diffusion process time.