One-pass antibacterial efficacy of bipolar air ions against aerosolized Staphylococcus epidermidis in a duct flow

Lee, S.G.,Hyun, J.,Hwa Lee, S.,Hwang, J. Pergamon Press ; Elsevier Science Ltd 2014 Journal of aerosol science Vol.69 No.-

While heating, ventilating, and air-conditioning (HVAC) systems can provide healthy and comfortable indoor environments, virtually any part of an HVAC system can support active microbial growth if sufficient nutrients are present. In this study, we introduced a methodology to enhance the one-pass antibacterial performance of air ions against aerosolized bacteria in a ventilation duct flow. Staphylococcus epidermidis (S. epidermidis) was aerosolized, mixed with the duct flow, and exposed to air ions generated by carbon fiber ionizers installed inside the duct. The S. epidermidis was then sampled at the exit of the duct and incubated to evaluate their cultivability as functions of the ion exposure time, ion concentration, and ion polarity. When the ionizers produced bipolar air ions for 2s, a high antibacterial efficiency of 85% was obtained when four ionizers were positioned both at the top and bottom walls of the duct in a configuration in which there were three changes in ion polarity (one positive ionizer, one negative ionizer, one positive ionizer, and one negative ionizer in series along the flow direction). When the ion exposure time was decreased to 0.2s, an antibacterial efficiency of 50% was realized by applying a configuration with seven changes in ion polarity. By using a scanning electron microscope (SEM), cell contraction of S. epidermidis caused by the bipolar ion treatment was observed.

全身性 『크립토콕쿠스』症 : 一剖檢症例報告

李聖洙,金相仁,金勇一,全鍾暉,宋宣普,玄瑗 서울대학교 1963 서울대학교 論文集 Vol.14 No.-

An autopsy case of disseminated cryptococcosis in a 20 year old Korean female has been reported. Both gelatinous and granulomatous lesions are observed in the lungs, liver, extrahepatic biliary system, spleen, pancreas, adrenals, kidneys, small intestine, lymphnodes, bone marrow, skin, and leptomeninges and brain. Large numbers of micro-organism, that are spherical or ovoid, non-sporulating, non-mycelial, yeast-like with evidence of budding measuring 5-20 microns in diameter, and with thick gelatinous capsules, are found in the lesions. These morpholomans, gical characteristics of the organisms are strongly consistant with cryptococcus neofor-although cultures of the organisms have been failed to be performed. The gelatinous lesions consist mainly of masses of micro-organisms with little inflammatory response, while the granulomatous lesions reveal numerous lymphocytes, plasma cells, epitheloid cells and macrophages frequently forming giant cells, occasional neutrophils and variable number of fibroblastic cells. In case, caseous or coagulative type of necrosis is observed, and these focal lesions contain many degenerated organisms in the periphery. Neutrophilic infiltration is meager, and calcification in the lesions is not observed. These anatomical changes characterized by non-suppurative and granulomatous reaction and by gelatinous appearance of the lesion appear to be distinctly different from other mycotic infections than cryptococcosis. In this case, extensive leptomeningeal and limited cerebral cortical involvement is assumed to have been a late event, that formed the probable direct cause of death of the patient. The portal of entry of the organisms in this case has been discussed with special emphasis on the respiratory tract infection. This is believed to be the first reported autopsy case of cryptococcosis in the Korean literature.

Collateral projection from the locus coeruleus to whisker-related sensory and motor brain regions of the rat

Lee, Sat-Byol,Beak, Suk K.,Park, Seung H.,Waterhouse, Barry D.,Lee, Hyun S. Wiley Subscription Services, Inc., A Wiley Company 2009 Journal of comparative neurology Vol.514 No.4

<P>The primary goal of this study was to examine whether the locus coeruleus (LC) provides collateral projections to whisker-related, sensorimotor brain regions. After injections of retrograde tracers into the primary sensory (S1) barrel field/primary whisker motor (M1) cortices, ventroposteromedial (VPM)/ventrolateral (VL) thalamic nuclei, or principal sensory trigeminal (Pr5)/facial motor (Mo7) nuclei, the distribution of double-labeled neurons within the LC was examined. Our observations indicated that a large number of individual LC cells provided axon collaterals to S1-M1 or VPM-VL regions, whereas only a few projected to Pr5-Mo7 nuclei. The laterality and the distribution of dual-projecting LC neurons were as follows. 1) The neurons projecting to the S1-M1 cortices were predominantly ipsilateral (96% ± 0.7%). Labeled neurons were located ventrally at the rostral pole but were evenly distributed along the dorsoventral aspect of the principal LC. 2) The cells projecting to the VPM-VL nuclei were bilateral, with ipsilateral (68% ± 2.3%) dominance. Neurons were observed at the rostrocaudal extent of the LC, where the labeling was most pronounced at the ventral, principal LC. 3) The neurons projecting to the Pr5-Mo7 regions exhibited slightly contralateral (56% ± 2.9%) dominance, where labeled cells were confined within the ventral margin of the principal subdivision. Taken together, the present observations demonstrate that each subdivision of the LC possesses a differential functional organization with respect to its collateral projection to whisker-related sensorimotor targets, suggesting that the nucleus might play a modulatory role in vibrissal sensorimotor integration that allows the guidance of behavioral action essential for the survival of the animal. J. Comp. Neurol. 514:387–402, 2009. © 2009 Wiley-Liss, Inc.</P>

Association of Extracellular Cleavage of E-Cadherin Mediated by MMP-7 with HGF-Induced in vitro Invasion in Human Stomach Cancer Cells

Lee, K.H.,Choi, E.Y.,Hyun, M.S.,Jang, B.I.,Kim, T.N.,Kim, S.W.,Song, S.K.,Kim, J.H.,Kim, J.-R. S. Karger AG 2007 European surgical research Vol.39 No.4

<P><I>Background:</I> Proteolytic shedding of the ectodomain of a variety of transmembrane proteins, including cell-to-cell adhesion molecules, has been observed in solid cancers. We have investigated whether extracellular cleavage of E-cadherin mediated by matrix metalloproteinase-7 (MMP-7) is involved in hepatocyte growth factor (HGF) induced in vitro invasion in stomach cancer cells. <I>Methods:</I> The effects of HGF on the expression of E-cadherin/β-catenin and MMP-7 at both the protein and mRNA levels were assessed in stomach cancer cells, NUGC-3 and MKN-28, and in cells in which the expression of MMP-7 was downregulated by transfection with a MMP-7 short hairpin RNA plasmid. <I>Results:</I> Treatment with HGF increased the extracellular cleavage of E-cadherin and the release of MMP-7 and reduced the level of E-cadherin in a dose- and time-dependent manner. HGF treatment repressed the phosphorylation of β-catenin in a Triton-soluble fraction, but enhanced this phosphorylation in a Triton-insoluble fraction. The association of E-cadherin with β-catenin was decreased by HGF treatment in the Triton-soluble fraction. In addition, treatment of MMP-7 short hairpin RNA transfected NUGC-3 cells with HGF resulted in no extracellular cleavage of E-cadherin and also decreased the in vitro cell invasion. <I>Conclusions:</I> These results suggest that incubation with HGF mediated the release of MMP-7, resulting in extracellular cleavage of E-cadherin from stomach cancer cells. This might be a key mechanism in HGF-induced in vitro invasion and metastasis.</P><P>Copyright © 2007 S. Karger AG, Basel</P>

평면형 Bi-Sb 다중접합 열전변환기의 특성

이현철,유호종,김진섭,함성호,신장규,이종현,이정희,권성원,박세일 경북대학교 센서기술연구소 1997 센서技術學術大會論文集 Vol.8 No.1

A planar Bi-Sb multijunction thermal converter for the precise measurements of ac voltage and current has been fabricated and its characteristics was discussed. In order to convert ac power into heat, a bifilar thin film Pt-heater, which could cancel its Thomson and Peltier effects, was prepared on the Si_(3)N_(4)/SiO_(2)/Si_(3)N_(4) diaphragm for the thermal isolation between heater and silicon substrate. To convert the temperature or the heat generated by the heater into dc voltage and current, hot and cold junctions of the Bi-Sb thermopile, which has a large difference in Seebeck coefficients, were formed on the dielectric diaphragm and the silicon substrate, respectively. The respective thermal sensitivity of the thermal converter with a bifilar heater was about 10.1 mV/mW and 14.8 mV/mW in the air and vacuum, which is about eight times higher than that of commercial 3-dimensional thermal converter. In the case of ac 2 V-input voltage, the ac-dc voltage transfer difference was about ±2.0 ppm, and in the case of ac 10 mA-input current, the ac-dc current transfer difference was about ± 0.6 ppm, in the frequency range from 10 Hz to 10 kHz.

Adsorption Equilibria and Enthalpy of Adsorption for Ammonia-Metal Chloride System

Kang, S.-M 한국화학공학회 1998 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.36 No.1

1,500m-Run 및 Sit-up이 力道選手에 미치는 影響

李學來,玄友泳,曺泳八,柳根碩 漢陽大學校 1972 論文集 Vol.6 No.-

In order to check the effects of physical training (1,500m-run, Sit-up) to weight lifter's stamina, 14 physical education major students are selected at random. And 7 in A group(training group) others in B group (control group) are given some exercises as table-Ⅰ. After 44 days training, we recheck the A.B. groups to confirm physiological change and physical fitness (see table 4,5,6,7,8,9). The results may be sumerized as follows : 1. A group's muscular strength improve more than B group's 2. The very "sit-up" training we had, assist the power. 3. 1,500m-run and Sit-up training may assist to build the weight lifter's stamina.

Performance of electrochemical double layer capacitors using highly porous activated carbons prepared from beer lees

Sang Guk Lee,Hee Moon,Kwang Hyun Park,심왕근,M.S. balathanigaimani 한국공업화학회 2011 Journal of Industrial and Engineering Chemistry Vol.17 No.3

Beer lees precursor is chosen to prepare activated carbons having different physical and chemical properties. The beer lees-based activated carbons (BL-ACs) are characterized by N2 adsorption/desorption isotherms, adsorption energy distributions (AEDs), and X-ray photoelectric spectroscopy (XPS). Furthermore the electrochemical properties of the BL-ACs are assessed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and constant current charge/discharge method. The maximum specific capacitance (about 188 F/g at discharge current of l mA/cm2) is obtained in 0.1 M H2SO4 electrolyte solution, which is a relatively low electrolyte concentration. The overall results suggest that the BL-ACs are good candidates for EDLC electrode materials.

Enhanced efficiency and stability of polymer solar cells using solution-processed nickel oxide as hole transport material

Parthiban, S.,Kim, S.,Tamilavan, V.,Lee, J.,Shin, I.,Yuvaraj, D.,Jung, Y.K.,Hyun, M.H.,Jeong, J.H.,Park, S.H. ELSEVIER 2017 Current Applied Physics Vol.17 No.10

<P>Solution-processed nickel oxide (s-NiOx) was synthesized for use as hole-transport layers (HTLs) in the fabrication of polymer solar cell (PSC) devices. The s-NiOx thin-films were deposited using spin-coating and post-annealed at 300 degrees C, 400 degrees C, or 500 degrees C. With increased annealing temperature, the nickel acetate precursor decomposes more fully and forms s-NiOx films that show larger crystalline grain sizes with lower root mean square surface roughness. Bulk heterojunction solar cells fabricated with the new random polymer RP(BDT-PDBT) and [6,6]-phenyl-C-70-butyric acid methyl ester (PC70BM) using s-NiOx as HTLs exhibit a 4.46% enhancement in power conversion efficiency and better stability compared to conventional PSCs using poly (3,4-ethylenedioxythiophene):poly(styrene sulfonate) as HTLs. We believe that the solution-processable and highly stable s-NiOx could be a potential alternative for functional interface materials in optoelectronic devices. (C) 2017 Elsevier B.V. All rights reserved.</P>

MGrid Portal : 분자 시뮬레이션 그리드 포탈

이종현(Lee Jong Hyun0 Kim),김동욱(D.W. Lee),이건영(K.Y. Jeong),정갑주(K.J. Hwang),황선태(S.T. Park),박형우(H.W.) 한국정보과학회 2004 한국정보과학회 학술발표논문집 Vol.31 No.1A

그리드 컴퓨팅은 다양한 이기종 분산 컴퓨팅 환경에서 다양한 소프트웨어들에 대한 설치, 운영, 업그레이드, 유지보수 등이 요구된다. 이러한 환경에서 응용 소프트웨어(특히, 레가시 소프트웨어) 지원은 매우 어려운 작업이다. 웹 포탈 기술은 이러한 문제에 대한 효과적 대안이다. 그러나 웹 포털의 경우 다양한 사용자 인터페이스 제공이 난해하여 긴밀한 사용자와 컴퓨터간 상호작용이 요구되는 응용과학 분야 연구에 적용이 어렵다. MGrid 포탈은 BT/NT분야에서 광범위하게 사용되는 연구기법인 분자 시뮬레이션을 지원하도록 설계된 그리드 포탈 시스템으로 분자 시뮬레이션 작업들에 대한 상세한 모니터링 및 통제 기능을 지원하도록 설계되어 있다.