• Title/Summary/Keyword: Polarity effect

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The Effect of Electrical Stimulation on Bacterial Growth (전기자극이 세균성장에 미치는 영향)

  • Park Young-Han;Kim Jin-Sang;Park Rae-Joon
    • The Journal of Korean Physical Therapy
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    • v.6 no.1
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    • pp.109-119
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    • 1994
  • The study was carried out to investigate the change of bacterial growth in vitro according to polarity, current intensity and time, to prepare the basic data for electrotherapy and clinical research. The Gram positive Staphylococcus aureus and Gram negative Escherichia coli 1mm infect wound were cultured in Trypticase Soy Brath and Trypticase Soy Agar. The results were as followings. 1. The current stimulated group was changed in bacterial growth according to polarity, current intensity and time respectively. 2. The bacteriolytic effect revealed in the anode but the inhibitory effect of bacterial growth revealed in the cathode. 3. The lumber of E. coli reduced after 6-hours but the numbers of S. aureus reduced after 2 hours in Trypticase Soy Brath. 4. The anode showed acid reaction and cathode showed alkaline reaction in Trypticase Soy Agar.

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Design of Double-Independent-Gate Ambipolar Silicon-Nanowire Field Effect Transistor (양극성 이중 독립 게이트 실리콘 나노와이어 전계 효과 트랜지스터 설계)

  • Hong, Seong-Hyeon;Yu, YunSeop
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.12
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    • pp.2892-2898
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    • 2015
  • We propose a new Double-Independent-Gate Ambipolar Silicon-Nanowire Field Effect Transistor(DIG Ambi-SiNWFET). The proposed transistor has two types of gate such as polarity gate and control gate. The polarity gate determines the operation that the gate bias controls NMOSFET or PMOSFET. The voltage of control gate controls the current characteristic of the transistor. We investigated systematically work functions of the two gates and source/drain to operate ambipolar current-voltage characteristics using 2D device simulator. When the work functions of polarity gate, control gate and source/drain are 4.75eV, 4.5eV, and 4.8eV, respectively, it showed the obvious ambipolar characteristics.

A Study on Factors Affecting the Effect of Blue Light Blocking in Sunscreen (자외선 차단제품에서 블루라이트 차단 효과에 영향을 주는 인자에 관한 연구)

  • Park, Soo Jin;Kwak, Byeong Mun;Lee, Mi Gi;Bin, Bum Ho
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.46 no.4
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    • pp.383-390
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    • 2020
  • Blue light is a blue-based light existing at a wavelength between 380 and 450 nm, and it has been reported that it induces active oxygen and causes aging, and accordingly, interest in the blue light blocking effect is increasing. In this study, the effects of the polarity of oil, viscosity of the formulation, type of emulsifier, emulsified particles, and inorganic UV blocking agents on the blue light blocking effect in UV blocking products were investigated. As a result, it was confirmed that the blue light blocking rate increased as the polarity of the oil became similar to that of the organic UV blocker, and the higher the viscosity of the formulation, the higher the blue light blocking rate. The types of emulsifiers and emulsified particles had little effect on the blue light blocking effect, and the presence of inorganic UV blocking agents was found to be one of the factors that greatly influenced the blue light blocking rate. These results can effectively increase the efficiency of blocking blue light, and may be used in the development of blue light blocking products and formulation research in the future.

Effect of Amino Terminus of Gap Junction Hemichannel on Its Channel Gating (간극결합채널의 아미노말단이 채널개폐에 미치는 영향)

  • Yim Jaegil;Cheon Misaek;Jung Jin;Oh Seunghoon
    • Journal of Life Science
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    • v.16 no.1
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    • pp.37-43
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    • 2006
  • Gap junction is an ion channel forming between adjacent cells. It also acts as a membrane channel like sodium or potassium channels in a single cell. The amino acid residues up to the $10^{th}$ position in the amino (N)-terminus of gap junction hemichannel affect gating polarity as well as current-voltage (I-V) relation. While wild-type Cx32 channel shows negative gating polarity and inwardly rectifying I-V relation, T8D channel in which threonine residue at $8^{th}$ position is replaced with negatively charged aspartate residue shows reverse gating polarity and linear I-V relation. It is still unclear whether these changes are resulted from the charge effect or the conformational change of the N-terminus. To clarify this issue, we made a mutant channel harboring cysteine residue at the $8^{th}$ position (T8C) and characterized its biophysical properties using substituted-cysteine accessibility method (SCAM). T8C channel shows negative gating polarity and inwardly rectifying I-V relation as wild-type channel does. This result indicates that the substitution of cysteine residue dose not perturb the original conformation of wild-type channel. To elucidate the charge effect two types of methaenthiosulfonate (MTS) reagents (negatively charged $MTSES^-$ and positively charged $MTSET^+$) were used. When $MTSES^-$ was applied, T8C channel behaved as T8D channel, showing positive gating polarity and linear I-V relation. This result indicates that the addition of a negative charge changes the biophysical properties of T8C channel. However, positively charged $MTSET^+$ maintained the main features of T8C channel as expected. It is likely that the addition of a charge by small MTS reagents does not distort the conformation of the N-terminus. Therefore, the opposite effects of $MTSES^-$ and $MTSETT^+$ on T8C channel suggest that the addition of a charge itself rather than the conformational change of the N-terminus changes gating polarity and I-V relation. Furthermore, the accessibility of MTS reagents to amino acid residues at the $8^{th}$ position supports the idea that the N-terminus of gap junction channel forms or lies in the aqueous pore.

Lubricating Performance of Polyalkylene Glycol and Polyolester Base Oils analyzed from the Model of Interaction between Environmentally adapted Polar base oils and Additive (TCP) (환경친화적인 극성기유와 첨가제(TCP)의 상호작용모델로부터 해석된 Polyalkylene glycol 및 Polyolester Base Oil의 윤활작용)

  • ;Masabumi Masuko
    • Tribology and Lubricants
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    • v.17 no.2
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    • pp.146-152
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    • 2001
  • Environmentally adapted synthetic base oils of polyalkylene glycols (PAGs) and polyol esters (POEs) show a high polarity because of their functional groups containing oxygen atom. The lubricating performance of these polar base oils was investigated by using a four-ball tribometer under boundary lubrication condition. Four polyalkylene glycols and five polyol ester base oils were used as sample base oils of high polarity. A mineral oil (MO) and alkylnaphthalene (AN) were used as low polarity base oils. Tricrecylphosphate (TCP) was added to all the base oils, in the range of 10 mmol/L-2000 mmol/L, as an antiwear additive. All the TCP-for-mutated base oils showed optimum concentration characteristics for minimizing wear. The order of optimum concentration of all the base oils was in a good accordance with the order of relative stability of TCP in base oils. The interaction model on solvation between additive and different polar base oils can expect the stability order of TCP. Thus, the model on solvation can explain well the order of optimum concentration of all the base oils, by using the effect of polarity (dielectric constant, $\varepsilon$) and molecular size (molecular weight, MW) of them on stability of TCP in polar base oils. Finally, a good correlation of the optimum concentration for all the base oils was obtained when it was arranged as a function of C∝(M $W_{Base Oil}$/M $W_{TCP}$)$^{-2}$.71/.($\varepsilon$$_{Base Oil}$)$^{3.38}$ by these two parameters.s..

Effect of ion-pair complexation with bile acids on the bilary excretion and systemic distribution of organic drugs

  • Shim, Chang-Koo
    • Archives of Pharmacal Research
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    • v.9 no.1
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    • pp.49-54
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    • 1986
  • Effect of sodium taurodeoxycholate (TDC) infused intravenously on the pharmacokinetics of methylene blue (MB) was studied in the rat to investigate the role of ion-pair complexation in the body on drug elimination and disposition. Distribution volume (Vd) of MB was increased significantly (p< 0.05) by TDC infusion. Considering together with the fact that apparent partition coefficient (APC) of MB between phosphate buffer (pH 7.4) and n-octanol was increased markedly by TDC, the increase in Vd seemed to be the result of decreased polarity of MB by ion-pair formation with TDC. But total body clearance (CLt) and biliary excretion clearance (CLbil) of MB were not increased significantly by TDC.

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Effect of Ganoderma lucidum Mycelial Fractions on the Functional Recovery of Primary Cultured Hepatocytes. (영지 균사체 분획이 일차배양 간세포 기능회복에 미치는 영향)

  • 박혜선;현진원;김하원;심미자;김병각
    • Microbiology and Biotechnology Letters
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    • v.28 no.4
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    • pp.209-213
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    • 2000
  • The cultured mycelia of Ganoderma lucidum were extracted and the extract was separated into six fractions by organic solvent fractionation. The antihepatotoxic activity of all the fractions was evaluated by measuring activities of glutamic pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT). Among the fractions tested, the high-polarity fractions such as aqueous and n-butanol fractions significantly reduced activities of GPT and GOT in CCl4- and galactosamine-intoxicated rat primary hepatocytes. When intracellular synthetic activities were measured by pulsing the rate primary cultured hepatocytes with [3H]-uridine and [3H]-leucine, activities of DNA, RNA and protein. When direct toxicities of the fractions were measured against human hepatoma(SK-Hep-1), the non-polarity fractions such as n-butanol and ethyl acetate fractions showed potent direct cytotoxicities even at the concentration of 1 $\mu\textrm{g}$/ml. These data showed that Ganoderma lucidum has hepatoprotective and hepatotoxic recovery principles in its mycelia.

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Characteristics of DC Surface Discharge for the Development of UV Camera (자외선 카메라 개발을 위한 직류 연면방전 특성)

  • Pang, Man-Sik;Choi, Jae-Hyeong;Kim, Woo-Jin;Kim, Young-Seok;Kim, Sang-Hyun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.5
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    • pp.98-103
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    • 2011
  • Recently, UV(ultra-violet rays) camera has attracted a great deal of interest from the view point of easy judgement in inspections and diagnoses of the safety of power equipment. Especilly, UV camera is applied the inspection of UV with corona discharge. One of the most important and difficult problems is the basic research of filter design, materials and corona discharge. In this paper, we will report on the UV generation, corona pulse count and the polarity effect of positive and negative DC surface discharge in air. Also, corona discharge characteristics are analyzed using prototype UV camera of Korea. UV generation and corona pulse count due to surface discharge in positive needle is higher than that of negative needle.

Breakdown Characteristics of a Vertical Sphere-Plane Air Gap in the Presence of Combustion Flame (수직배치 구대평판 공기 갭에서 연소화염 존재시의 절연파괴 특성)

  • Kim, In-Sik
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.5
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    • pp.79-84
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    • 2011
  • In this study, breakdown characteristics of a vertical sphere-plane air gap in the presence of combustion flame were examined under the application of a.c. and d.c. high-voltages in order to investigate the effect of flame on the dielectric strength of air. Propane gas is used as the fuel of the flame, and the temperature distribution of air around the flame is measured. The polarity effects for the d.c. voltages and breakdown voltages of air when applied both of a.c. and d.c. voltages were examined in the case of the variation of the gap length and the horizontal distance between the flame and the high-voltage sphere electrode. The influence of relative air density, electrification and shape changes of the flame as factors that affect the breakdown voltages were discussed.