• Title/Summary/Keyword: concentration response functions

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Electrochemical Growth of Palladium Nanowire for Highly Sensitive Hydrogen Sensor (고감도 수소센서를 위한 팔라듐 나노선의 전기화학적인 성장)

  • Jo, S.Y.;Kang, B.R.;Im, Y.H.
    • Journal of Energy Engineering
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    • v.19 no.1
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    • pp.21-24
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    • 2010
  • We present a novel electrochemical method to fabricate a single Pd nanowire based on direct current assisted dielectropheresis (DEP) process between two predefined metal electrodes. The electrochemical methods was investigated as functions of frequency and voltage for optimal growth conditions of Pd nanowire. The synthesized Pd nanowire have a good resistance of $1\;k{\Omega}$, diameters of several hundred nanometers on average and lengths of $8\;{\mu}m$. Finally, the single Pd nanowire was capable of detecting hydrogen in the concentration range from 100 to 2500 ppm with high sensitivity and response time, thus demonstrating its suitability for use as a hydrogen sensor.

Pro-Inflammatory Role of S1P3 in Macrophages

  • Heo, Jae-Yeong;Im, Dong-Soon
    • Biomolecules & Therapeutics
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    • v.27 no.4
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    • pp.373-380
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    • 2019
  • Sphingosine kinase 1 and its product, sphingosine 1-phosphate (S1P), as well as their receptors, have been implicated in inflammatory responses. The functions of receptors $S1P_1$ and $S1P_2$ on cell motility have been investigated. However, the function of $S1P_3$ has been poorly investigated. In this study, the roles of $S1P_3$ on inflammatory response were investigated in primary peritoneal macrophages. $S1P_3$ receptor was induced along with sphingosine kinase 1 by stimulation of lipopolysaccharide (LPS). LPS treatment induced inflammatory genes, such iNOS, COX-2, $IL-1{\beta}$, IL-6 and $TNF-{\alpha}$. TY52156, an antagonist of $S1P_3$ suppressed the induction of inflammatory genes in a concentration dependent manner. Suppression of iNOS and COX-2 induction was further confirmed by western blotting and NO measurement. Suppression of $IL-1{\beta}$ induction was also confirmed by western blotting and ELISA. Caspase 1, which is responsible for $IL-1{\beta}$ production, was similarly induced by LPS and suppressed by TY52156. Therefore, we have shown $S1P_3$ induction in the inflammatory conditions and its pro-inflammatory roles. Targeting $S1P_3$ might be a strategy for regulating inflammatory diseases.

Hydrogen Sulfide Poisoning (황화수소 중독 증례)

  • Choi, Young-Hee;Nam, Byung-Kuk;Kim, Hyo-Kyung;Park, Ji-Kang;Hong, Eun-Seog;Kim, Yang-Ho
    • Journal of The Korean Society of Clinical Toxicology
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    • v.2 no.1
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    • pp.31-36
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    • 2004
  • Three workers, field operators in lubricating oil processing of petroleum refinery industry were found unconscious by other worker. One of them who were exposed to an high concentration of H2S was presented with Glasgow Coma Score of 5, severe hypoxemia on arterial blood gas analysis, normal chest radiography, and normal blood pressure. On hospital day 7, his mental state became clear, and neurologic examination showed quadriparesis, profound spasticity, increased tendon reflexes, abnormal Babinski response, and bradykinesia. He was also found to have decreased memory, attention deficits and blunted affect which suggest general cognitive dysfunction, which improved soon. MRI scan showed abnormal signals in both basal ganglia and motor cortex, compatible with clinical findings of motor dysfunction. Neuropsychologic testing showed deficits of cognitive functions. SPECT showed markedly decreased cortical perfusion in frontotemporoparietal area with deep white matter. Another case was recovered completely, but the other expired the next day.

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Characteristics of Purinergic Receptor Expressed in 3T3-L1 Preadipocytes

  • Lee, Hyung-Joo;Baik, Joon-Heum;Kim, Min-Jeong;Kim, Na-Hyun;Kong, In-Deok
    • Biomedical Science Letters
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    • v.15 no.4
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    • pp.319-326
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    • 2009
  • Extracellular ATP elicits diverse physiological effects by binding to the G-protein-coupled P2Y receptors on the plasma membrane. In addition to the short-term effects of extracellular nucleotides on cell functions, there is evidence that such purinergic signalling can have long-term effects on cell proliferation, differentiation and death. The 3T3-L1 cell line derived from mouse embryo is a well-established and commonly utilized in vitro model for adipocytes differentiation and function. However, the distributions and roles of P2Y subtypes are still unknown in the preadipocyte. In this study, we identified the distributions and roles of P2Y subtypes in preadipocyte using $Ca^{2+}$ imaging and realtime PCR. ATP increased the $[Ca^{2+}]_i$ in a concentration-dependent manner. ATP increased $Ca^{2+}$ in absence and/or presence of extracellular $Ca^{2+}$. Suramin, non-selective P2Y blocker, largely blocked the ATP-induced $Ca^{2+}$ response. U73122, a PLC inhibitor, completely inhibited $Ca^{2+}$ mobilization in 3T3-L1 cells. The mRNA expression by realtime PCR of P2Y subtypes was $P2Y_2:P2Y_5:P2Y_6=1.0:12.5:0.3$. In conclusion, we showed that $P2Y_5$ receptor is a dominant purinergic receptor in preadipocytes, and multiple P2Y receptors could involve in differentiation and migration via regulating of intracellular calcium concentration.

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Performance Analysis of Interworking Model for a Broadband Access Network with VB5.2 Interface (광대역 액세스 망의 VB5.2 인터페이스를 위한 연동 모델의 성능분석)

  • Kim, Choon-Hee;Cha, Young-Wook;Han, Ki-Jun
    • Journal of KIISE:Information Networking
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    • v.27 no.2
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    • pp.237-246
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    • 2000
  • A broadband access network in B-ISDN subscriber network, plays a role of concentration or multiplexing of various subscribers into a service node. For call and connection control functions, DSS2 and B-ISUP signalling protocols are standardized for each of a subscriber side and a network node. B-BCC and B-ANCC protocol were proposed for VB5.2 interface. This interface allows dynamic control of ATM connections at the broadband access network. To establish an end-to-end ATM connection, interworking functions between VB5.2 interface's connection control protocol and the signalling protocol, are performed at the service node. A sequential interworking model and a parallel interworking model were proposed for these interworking functions. The sequential interworking model recommended by ITU-T causes an overall connection setup delay by introducing the access network, because this model proceeds the signalling protocol of network node after the response of VB5.2 interface protocol. On the other hand, the parallel interworking model proceeds the signalling protocol and the VB5.2 interface protocol simultaneously. The simultaneity of the parallel interworking model minimizes the overall connection setup delay. In this paper, we analyze and simulate above two interworking models with B-BCC or B-ANCC protocol in terms of a connection setup delay and completion ratio.

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Damage Evaluation of Glass Fiber/PET Composite Using Acoustic Emission Method (음향방출법을 이용한 Glass Fiber/PET 복합재료의 손상평가)

  • 김상태;김덕윤
    • Composites Research
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    • v.14 no.1
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    • pp.1-7
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    • 2001
  • In this study, damage evaluation of glass fiber reinforced thermoplastic composites was investigated with acoustic emission method. Specimens of 1.7mm thickness laminate were made from PET and 7 layers o171ass fabrics. Notch and impact loading were added to the specimen and normal tensile test and tensile test with the dead load were carried out. AE signal was measured as the functions of notch ratio to the width0 and impact energy in order to find out the correlation between fracture mode and AE parameters. The result has shown that low amplitude of AE signal was due to the microcrack of matrix and its growth, whereas the amplitude in the mid range was the response to the delamination and interfacial separation. In the range of high amplitude above 90dB. the fracture of glass fabric was found. Tensile strength decreased with increasing notch ratio to the width and impact energy because of tile effect or delamination, the cracking of matrix and stress concentration. In proportion to the size of damaged area. AE signal showed its wider range of frequency and energy as well as increased number of hits.

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The Change of K-MMSE Following Donepezil Medication in Patients with Alzheimer's Disease and Small Vessel Dementia, and the Characteristics of Alzheimer's Disease with Meaningful K-MMSE Change (알쯔하이머병과 소혈관성 치매에서 Donepezil 복용 후 K-MMSE의 변화와 의미 있는 K-MMSE 변화를 보이는 알쯔하이머병 환자의 특징)

  • Kwak, Yong Tae;Han, Il-Woo;Kim, June;Lee, Yu-Sang
    • Korean Journal of Biological Psychiatry
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    • v.12 no.2
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    • pp.98-106
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    • 2005
  • Objectives:Donepezil is a widely used drug for the treatment of patients with Alzheimer's disease(AD). The aim of the present study was to clarify the efficacy and the characteristics of responders to donepezil. Methods:Patients with probable AD(n=80;75.7 years) and small vessel dementia(SVD)(n=18;77.8 years) who received donepezil were retrospectively analyzed using Alzheimer's registry, and three questions were asked:1) Does donepezil therapy improves cognitive symptoms in patients with dementia? 2) If donepezil improves cognitive symptoms, which items of the K-MMSE are improved? 3) What are the characteristics of responder to donepezil medication? Results:1) After donepezil medication, cognitive function measured by the K-MMSE was significantly improved in both types of dementia(AD and SVD), However, statistical differences were not found between these groups. 2) In a clinical trial of donepezil, the patients performed better than before mediation on K-MMSE items assessing orientation, recall, construction, concentration, calculation. 3) In AD, the K-MMSE score before medication was closely related with response of donepezil. Conclusion:This study suggests that donepezil improves various cognitive functions in both types of dementia, and the responsive group had significantly lower K-MMSE scores than the non-responsive group before medication.

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Inhibitory Effect of Salvia officinalis on the Inflammatory Cytokines and Inducible Nitric Oxide Synthasis in Murine Macrophage RAW264.7 (RAW 264.7 Cell에서 세이지에 의한 염증성 Cytokine 및 iNOS억제 효과)

  • 현은아;이혜자;윤원종;박수영;강희경;김세재;유은숙
    • YAKHAK HOEJI
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    • v.48 no.2
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    • pp.159-164
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    • 2004
  • Primary pro-inflammatory cytokines are a trio: tumor necrosis- $\alpha$ (TNF-$\alpha$), interleukine-$\beta$ (IL-$\beta$), and interleukine-6 (IL-6). These cytokines initiate and regulate the acute-phase inflammatory response during infection, trauma, or stress and appear to play an important role in the immune process. Nitric oxide (NO) is a multi-functional mediator, which plays an important role in regulating various biological functions in vivo. NO production by inducible nitric oxide synthase (iNOS) in macrophages is essential for the defense mechanisms against microorganisms and tumor cells. However, over-expression of iNOS by various stimuli, resulting in over-production of NO, contributes to the pathogenesis of septic shock and some inflammatory and auto-immune disease. Solvent fractions of sage ( Salvia officinalis L.), which is cultivated in Jeju-Do, was assayed for their effects on TNF-$\alpha$ and IL-6 production in LPS-stimulated RAW 264.7 macrophages. Hexane and ethylacetate (EtOAc) fraction of sage inhibited the protein and mRNA expression of TNF-$\alpha$ and IL-6 in LPS stimulated RAW 264.7 cells at the concentration of 100 $\mu\textrm{g}$/$m\ell$. Also, incubation of RAW 264.7 cells with the fraction of hexane or EtOAc (50 $\mu\textrm{g}$/$m\ell$) inhibited the LPS induced nitrite accumulation and the LPS/IFN-${\gamma}$ induced iNOS protein. And this inhibition of iNOS protein is concordant with the inhibition of iNOS mRNA expression. Above results suggest that extract of sage may have anti-inflammatory activity through the inhibition of pro-inflammatory cytokines (TNF-$\alpha$, IL-1$\beta$, IL-6), iNOS and NO.

Fermentation-Mediated Enhancement of Ginseng's Anti-Allergic Activity against IgE-Mediated Passive Cutaneous Anaphylaxis In Vivo and In Vitro

  • Hwang, Seon-Weon;Sun, Xiao;Han, Jun-Hyuk;Kim, Tae-Yeon;Koppula, Sushruta;Kang, Tae-Bong;Hwang, Jae-Kwan;Lee, Kwang-Ho
    • Journal of Microbiology and Biotechnology
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    • v.28 no.10
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    • pp.1626-1634
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    • 2018
  • Ginseng (the root of Panax ginseng Meyer) fermented by Lactobacillus plantarum has been found to attenuate allergic responses in in vitro and in vivo experimental models. Ginseng has been reported to also possess various biological functions including anti-inflammatory activity. The present study was aimed at comparing the anti-allergic effect of ginseng and fermented ginseng extracts on IgE-mediated passive cutaneous anaphylaxis in vitro in a murine cell line and in vivo in mice. Fermented ginseng extract (FPG) showed higher inhibitory effect against in vitro and in vivo allergic responses when compared with ginseng extract (PG). The secretion of ${\beta}$-hexosaminidase and interleukin (IL)-4 from the IgE-DNP-stimulated RBH-2H3 mast cells were significantly (p < 0.05) inhibited by FPG treatment, and this effect was concentration-dependent. Further, MKK4 activation and subsequent JNK phosphorylation were attenuated by FPG treatment. The inhibitory effect of FPG on the in vitro allergic response was verified in vivo against IgE-DNP-induced passive cutaneous anaphylaxis in a mouse model. These data indicated that the fermentation of ginseng with L. plantarum enhanced its anti-allergic effects both in vitro and in vivo. We predict that compositional changes in the ginsenosides caused by the fermentation may contribute to the change in the anti-allergic effects of ginseng. The results of our study highlight the potential of the use of FPG as a potential anti-allergic agent.

Proline Accumulation and P5CS ($\Delta^1$-pyrroline-5-carboxylate synthetase) Gene Expression in Response to Salt Stress in Zoysiagrasses

  • Lee, Dong-Joon;Hwang, Cheol-Ho
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.48 no.1
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    • pp.20-24
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    • 2003
  • Proline is known as an osmotrotectant to enhance tolerance against both salt and dehydration stresses. A P5CS ($\Delta^1$-pyrroline-5-carboxylate synthetase) plays a major role in regulation of synthesis of proline. An overexpression of the mothbean P5CS gene in transgenic tobacco plant increased the levels of proline and osmotolerance. In an attempt to look for the possibility to use content of proline as well as a level of P5CS gene expression as molecular markers for salt tolerance, the amounts of proline and transcript levels of P5CS were measured as functions of either concentration of NaCl or length of treatment period among different species of zoysiagrass. Hybridzoysia showed the highest level of proline ($329\mu\textrm{g}$/g.f.w.) among five different species of zoysiagrass at 250 mM NaCl in 24 hours. The level of P5CS transcript was also the highest in the hybridzoysia at 250 mM NaCl in 24 hours. The transcriptions of P5CS gene were induced at the rates of 1.2, 1.2, 1.8, and 1.8, upon treatment of 250 mM NaCl in Z. japonica, Z. matrella, Z. sinica and hybridzoysia respectively. Based on a correlation between the level of P5CS transcript and the proline content among different species of zoysiagrass, a comparative structural analysis of the gene for P5CS from either Z. sinica or hybridzoysia may lead to an understanding of mechanism for salt tolerance shown differently among zoysiagrasses.