• Title/Summary/Keyword: Constant potential

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Characterization of the Nickel Resistance Gene from Legionella pneumophila: Attenuation of Nickel Resistance by ppk (polyphosphate kinase) Disruption in Escherichia coli

  • Hahm, Dae-Hyun;Yeon, Mi-Jung;Ko, Whae-Min;Lee, Eun-Jooh;Lee, Hye-Jung;Shim, In-Sop;Kim, Hong-Yeoul
    • Journal of Microbiology and Biotechnology
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    • v.12 no.1
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    • pp.114-120
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    • 2002
  • A 1,989-bp genomic region encoding nickel resistance genes was isolated from Legionella pneumophila, a pathogen for legionellosis. From a sequencing and computer analysis, the region was found to harbor two structural genes, a nreB-like protein gene (1,149 bp) and a nreA-like protein gene (270 bp), in a row. Both genes exhibited a significant degree of similarity to the corresponding genes from Synechocystis sp. PCC6803 ($54\%$ amino acid sequence identity) and Achromobacter xylosoxidans 31A ($76\%$). The gene was successfully expressed in E. coli MG1655 and conferred a nickel resistance of up to 5 mM in an LB medium and 3 mM in a TMS medium including gluconate as the sole carbon source. E. coli harboring the nickel resistance gene also exhibited a substantial resistance to cobalt, yet no resistance to cadmium or zinc. Since the extracellular concentration of nickel remained constant during the whole period of cultivation, it was confirmed that the nickel resistance was provided by an efflux system like the $Ni^2+$permease (nrsD) of Synechocystis sp. strain PCC6803. Since polyphosphate (poly-P) is known as a global regulator for gene expression as well as a potential virulence factor in E. coli, the nickel resistance of a ppk mutant of E. coli MG 1655 harboring the nickel resistance gene from L. pneumophila was compared with that of its parental strain. The nickel resistance was significantly attenuated by ppk inactivation, which was more pronounced in an LB medium than in a TMS medium.

Study on the Realities in Seoul Subway Crimes: Criminal Psychology (서울지하철 범죄 실태에 대한 범죄심리학적 연구)

  • Rim, Sang-Gon
    • Korean Security Journal
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    • no.7
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    • pp.233-285
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    • 2004
  • ‘Defined legally as a violation of law' (Sutherland, E. H. Principles of Criminology, Lippincott, Chicago, 1939) Crime within the group is essentially and primarily antisocial in that the criminal who is welfare of his group acts instead against it and breaks the principles of social solidarity not merely by not doing what these principles prescribe, but by doing something exactly opposites. Any program set up to attack crime and delinquent behavior at their sources. A program of his nature needs the constant and comprehensive collaboration of psychiatrists, social works, educations, lawmakers, and public officials, since crime is a social problem and it should be treated as such. Some crime preventives which should be mentioned are as follows, (1) The insurance that every child will be decently born and that his home life be socially and economically adequate; without socially mature parents the chid is handicapped at the start; thus parental education, integrated with the public school system, should be developed now. (2) A more meaningful educational program which would emphasize ideals of citizenship, moral integrity, and respect for the law and the police. (3) A periodic check made for potential delinquents throughout the public schools and treatment provided if possible; and if not, proper segregation in institutions. (4) Careful attention paid to press, movies, and radio so that crime may no longer appear to be glamorous. This can be done by women's clubs, civic bodies, and other educational groups exerting pressure on the movie syndicates and broadcasting companies to free their productions of the tawdry and lurid characteristics of crime and criminals. Aggression associated with the phallic stage of development, The child ordinarily comprehends sexual intercourse as an aggressive and sadistic act on the part of the male, and specifically on the part of the penis. Evidence that the penis is phantasied as a weapon of violence and destruction come from unconscious productions of normal adults. Limerick, for instance, often refer to the penis as square, or too large, etc., so that intercourse is dangerous and painful for the partner, This may wall be a projection of the male's own fear of coitus. A certain portion of the death-instinct always remains within the person; it is called 'primal sadism' and according to Freud is identical with masochism. 'After the chief part of it(the death instinct) has been directed outwards towards objects, there remains as a residuum within the organism the true erotogenic masochism, which on the one hand becomes a component of the libido and on the other still has the subject itself for a object.' Criminalism, compulsive-neurotic frequent repetition of criminal acts in a compulsive manner. Like most symptoms of the compulsive-neurotic, such antisocial act are closely rated to feelings of hostility and aggression, often against the father. Because these acts are symptomatic, they afford only temporary relief and are therefore repeated. One patient with compulsive-neurotic criminalism was apprehended after breaking into hardware store and stealing money. He later confessed to many similar incidents over the preceding two years. At the same time it was apparent that he stole only for the sake of stealing. He did not need the money he thus obtained and had no special plans for using it.

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olymerization behavior and thermal characteristics of two new composites at five temperatures: refrigeration to preheating

  • Jafarzadeh-Kashi, Tahereh Sadat;Mirzaii, Marzieh;Erfan, Mohmmad;Fazel, Akbar;Eskandarion, Solmaz;Rakhshan, Vahid
    • The Journal of Advanced Prosthodontics
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    • v.3 no.4
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    • pp.216-220
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    • 2011
  • PURPOSE. Heat of composite polymerization (HP) indicates setting efficacy and temperature increase of composite in clinical procedures. The purpose of this in vitro experimental study was to evaluate the effects of 5 temperatures on HP of two new composites. MATERIALS AND METHODS. From each material (Core Max II [CM] and King Dental [KD]), 5 groups of 5 specimens each were prepared and their total HPs (J/gr) were measured and recorded, at one of the constant temperatures $0^{\circ}C$, $15^{\circ}C$, $23^{\circ}C$, $37^{\circ}C$ and $60^{\circ}C$ ($2{\times}5{\times}5$ specimens) using a differential scanning calorimetry (DSC) analyzer. The data were analyzed using a two-way ANOVA, a Tukey's test, an independent-samples ttest, and a linear regression analysis (${\alpha}=0.05$). RESULTS. No polymerization reactions occurred at $0^{\circ}C$; then this temperature was excluded from statistical analyses. The mean HP of the remaining 20 KD specimens was $20.5{\pm}14.9$ J/gr, while it was $40.7{\pm}12.9$ J/gr for CM. The independent-samples t-test showed that there were significant differences between the HP of the two materials at the temperatures $15^{\circ}C$ (P=.0001), $23^{\circ}C$ (P=.0163), $37^{\circ}C$ (P=.0039), and $60^{\circ}C$ (P=.0106). Linear regression analysis showed statistically significant correlations between environment temperatures and HP of CM ($R^2=0.777$). CONCLUSION. Using CM is advantageous over conventional composite because of its better polymerization capacity. However due to its high HP, further studies should assess its temperature increase in vivo. Preheating KD is recommended. Refrigerating composites can negatively affect their polymerization potential.

Determination of Personnel Exposures in the Lower Energy Ranges of X-Ray by Photographic Dosimeter (저(低)에너지 X-선장(線場)에서 필름배지에 의한 개인피폭선량(個人被曝線量)의 결정(決定))

  • Ha, C.W.;Kim, J.R.;Suh, K.W.
    • Journal of Radiation Protection and Research
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    • v.11 no.1
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    • pp.57-64
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    • 1986
  • This paper described an improved technical method required for proper evaluation of personnel exposures by means of the photographic dosimeter developed by KAERI in lower gamma or X-ray energy regions, with which response of the dosimeter varies significantly. With calibration of the dosimeter in the energy range from 30 to 300 keV, the beam spectrum was carefully selected and specified it adequately. The absorber combinations and absorber thickness used to obtain the specified X-ray spectra from a constant potential X-ray machine were determined theoretically and also experimentally. A correlation between the density and exposure for the four separate energies, such as $49\;keV_{eff},\;154\;keV_{eff}\;250\;keV_{eff}\;and\;662\;keV$, is experimentally determined. As a result, it can be directly evaluated the exposure from the measured response of dosimeter.

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Development of Smart Multi-function Ground Resistivity Measuring Device using Arduino in Wind Farm (풍력 발전단지내 아두이노를 활용한 스마트 다기능 대지 고유 저항 측정 장치 개발)

  • Kim, Hong-Yong;Yoon, Dong-Gi;Shin, Seung-Jung
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.19 no.6
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    • pp.65-71
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    • 2019
  • Conventional methods of measuring ground resistance and ground resistance field measurement are used to measure voltage drop according to the resistance value of the site by applying current by installing a constant interval of measurement electrode. If the stratified structure of the site site is unique, errors in boundary conditions will occur in the event of back acid and the analysis of the critical ground resistance in the ground design will show much difference from simulation. This study utilizes the Arduino module and smart ground measurement technology in the convergent information and communication environment to develop a reliable smart land resistance measuring device even if the top layer of land is unique, to analyze the land resistance and accumulate data to predict the change in the age of the land. Considering the topographical characteristics of the site, we propose a ground resistance measuring device and its method of measuring ground resistance so that the auxiliary electrode can be installed by correctly positioning the angle and distance in measuring ground resistance. Not only is ground resistance value obtained through electrodes installed to allow accurate ground resistance values to be selected, but it can also be used as a useful material for installing electrical facilities in similar areas. Moreover, by utilizing reliable data and analyzing the large sections of the site, a precise analysis of the site, which is important in ground design as well as construction cost, is expected to be used much in ground facility design such as potential rise.

The Langmuir Adsorption Isotherms of the Electroadsorbed Hydrogens at the Single Crystal Pt(100)/Aqueous Electrolyte Interfaces (단결정 Pt(100)/수용액 계면에서 전가흡착된 수소의 Langmuir흡착등온식)

  • Chun Jang Ho;Jeon Sang Kyoo
    • Journal of the Korean Electrochemical Society
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    • v.4 no.1
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    • pp.14-20
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    • 2001
  • The Langmuir adsorption isotherms of the under-potentially deposited hydrogen (UPD H) and the over-potentially deposited hydrogen (OPD H) at the single crystal Pt(100)/0.5 M $H_2SO_4$ and 0.5 M LiOH aqueous electrolyte interfaces have been studied using the phase-shift method. The phase-shift profile $({-\varphi}\;vs.\;E)$ for the optimum intermediate frequency can be used as a useful method to estimate the Langmuir adsorption isotherm $(\theta\;vs.\;E)$ at the interfaces. The equilibrium constant (K) for the OPD H and the standard free energy $({\Delta}G_{ads})$ of the OPD H at the Pt(100)/0.5M $H_2SO_4$ aqueous electrolyte interface are $1.5\times10^{-4}$ and 21.8 kJ/mol, respectively. At the Pt(100)/0.5 LiOH aqueous electrolyte interface, K transits from 1.9(UPD H) to $6.8\times10^{-6}$(OPD H) depending on the cathode potential (E) and vice versa. Similarly, ${\Delta}G_{ads}$ transits -1.6 kJ/mol (UPD H) to 29.5 kJ/mol (OPD H) depending on E and vice versa. The transition of K and ${\Delta}G_{ads}$ is attributed to the two distinct adsorption sites of the UPD H and OPD H on the Pt(100) surface. The UPD H and the OPD H at the Pt(100) interfaces are the independent processes depending on the H adsorption sites rather than the sequential processes for the cathodic $H_2$ evolution reactions.

Analysis on the Electrode Kinetic Parameters at the Pd/LiOH Electrolyte Interface using the Phase-shift Method (위상이동 방법에 의한 Pd/LiOH 전해질 계면의 전극속도론적 패러미터 해설)

  • Chun Jang Ho;Mun Kyeong Hyeon;Cho Sung Chil;Son Kwang Chul
    • Journal of the Korean Electrochemical Society
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    • v.2 no.2
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    • pp.70-74
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    • 1999
  • The electrode kinetic parameters at the Pd/0.5 M LiOH electrolyte interface have been qualitatively studied using the phase-shift method. The phase shift $(\phi)$ depends on both the cathode potential (E>0) and frequency (f), and $\theta$ is inversely proportional to the fractional surface coverage $\theta$. At an intermediate frequency (10 Hz), the phase-shift profile $(\phi\;vs.\;E)$ can be related to the fractional surface coverage $(\theta\;vs.\;E)$. The phase-shift method can be used to estimate or plot the Frumkin adsorption isotherm. The rate (r) of change of the free energy of adsorption with $({\theta})$ is 22.3 kJ/mol. The equilibrium constant (K) for adsorption and the standard free energy $({\Delta}G_{\theta})$ of the adsorbed hydrogen atom $(H_{ads})$ are $3.7\times10^{-3}{\Delta}G_{\theta}>-8.4kJ/mol$, respectively. For 1$0.38>\theta>0$, the energy liberation or the exothermic reaction for hydrogen adsorption at the Pd cathode can be occurred. The electrode kinetic parameters $(r,\;K,\;{\Delta}G_{\theta}$ depend on the fractional surface coverage $({\theta})$ or the phase shift $(\phi)$.

Tyrosinase Inhibitory Activities of Meso-dihydroguaiaretic Acid from Machilus thunbergii (후박나무에서 분리한 Meso-dihydroguaiaretic acid의 tyrosinase 저해활성)

  • Kwon, Hyun Sook;Lee, Kyung Dong;Kim, Su Cheol;Cho, Soo Jeong
    • Journal of Life Science
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    • v.25 no.11
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    • pp.1298-1303
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    • 2015
  • Machilus thunbergii (Lauraceae) is an evergreen tree cultivated in Korea and Japan. M. thunbergii has long been used as a traditional medicine in Korea, China, and Japan to treat various diseases, including edema, abdominal pain, and abdominal distension. In this study, dried stem bark of M. thunbergii extracted in methanol and extract was partitioned into n-hexane, CHCl3, and BuOH. The CHCl3-soluble extracts chromatographed on silica gel column using a CHCl3/acetone and n-hexane/EtOAc mixture to afford Compound 1 and 2. Two dibenzylbutane lignans, macelignan (1) and meso-dihydroguaiaretic acid (2), were isolated from the CHCl3-soluble extract of M. thunbergii stem bark. The structures of 1 and 2 were determined by 1H- and 13C-NMR spectroscopic data analyses and a comparison with literature data. The tyrosinase inhibitory activity of the isolated compounds was evaluated. Among these compounds, Compound 2 strongly inhibited the monophenolase (IC50=10.2 μM) activity of tyrosinase. A kinetic analysis showed that Compound 2 was a competitive inhibitor. The apparent inhibition constant (Ki) for Compound 2 binding to free enzyme was 4.8 μM. Based on these results, it can be concluded that meso-dihydroguaiaretic acid (2) is a potential candidate for the treatment of melanin biosynthesis-related skin diseases.

Modeling the effects of excess water on soybean growth in converted paddy field in Japan 1. Predicting groundwater level and soil moisture condition - The case of Biwa lake reclamation area

  • Kato, Chihiro;Nakano, Satoshi;Endo, Akira;Sasaki, Choichi;Shiraiwa, Tatsuhiko
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.315-315
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    • 2017
  • In Japan, more than 80 % of soybean growing area is converted fields and excess water is one of the major problems in soybean production. For example, recent study (Yoshifuji et al., 2016) suggested that in the fields of shallow groundwater level (GWL) (< 1m depth), rising GWL even in a short period (e.g. 1 day) causes inhibition of soybean growth. Thus it becomes more and more important to predict GWL and soil moisture in detail. In addition to conventional surface drainage and underdrain, FOEAS (Farm Oriented Enhancing Aquatic System), which is expected to control GWL in fields adequately, has been developed recently. In this study we attempted to predict GWL and soil moisture condition at the converted field with FOEAS in Biwa lake reclamation area, Shiga prefecture, near the center of the main island of Japan. Two dimensional HYDRUS model (Simuinek et al., 1999) based on common Richards' equation, was used for the calculation of soil water movement. The calculation domain was considered to be 10 and 5 meter in horizontal and vertical direction, respectively, with two layers, i.e. 20cm-thick of plowed layer and underlying subsoil layer. The center of main underdrain (10 cm in diameter) was assumed to be 5 meter from the both ends of the domain and 10-60cm depth from the surface in accordance with the field experiment. The hydraulic parameters of the soil was estimated with the digital soil map in "Soil information web viewer" and Agricultural soil-profile physical properties database, Japan (SolphyJ) (Kato and Nishimura, 2016). Hourly rainfall depth and daily potential evapo-transpiration rate data were given as the upper boundary condition (B.C.). For the bottom B.C., constant upward flux, which meant the inflow flux to the field from outside, was given. Seepage face condition was employed for the surrounding of the underdrain. Initial condition was employed as GWL=60cm. Then we compared the simulated and observed results of volumetric water content at depth of 15cm and GWL. While the model described the variation of GWL well, it tended to overestimate the soil moisture through the growing period. Judging from the field condition, and observed data of soil moisture and GWL, consideration of soil structure (e.g. cracks and clods) in determination of soil hydraulic parameters at the plowed layer may improve the simulation results of soil moisture.

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Development of Free Flow Speed Estimation Model by Artificial Neural Networks for Freeway Basic Sections (인공신경망을 이용한 고속도로 기본구간 자유속도 추정모형개발)

  • Kang, Jin-Gu;Chang, Myung-Soon;Kim, Jin-Tae;Kim, Eung-Cheol
    • Journal of Korean Society of Transportation
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    • v.22 no.3 s.74
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    • pp.109-125
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    • 2004
  • In recent decades, microscopic simulation models have become powerful tools to analyze traffic flow on highways and to assist the investigation of level of service. The existing microscopic simulation models simulate an individual vehicle's speed based on a constant free-flow speed dominantly specified by users and driver's behavior models reflecting vehicle interactions, such as car following and lane changing. They set a single free-flow speed for a single vehicle on a given link and neglect to consider the effects of highway design elements to it in their internal simulation. Due to this, the existing models are limitted to provide with identical simulation results on both curved and tangent sections of highways. This paper presents a model developed to estimate the change of free-flow speeds based on highway design elements. Nine neural network models were trained based on the field data collected from seven different freeway curve sections and three different locations at each section to capture the percent changes of free-flow speeds: 100 m upstream of the point of curve (PC) and the middle of the curve. The model employing seven highway design elements as its input variables was selected as the best : radius of curve, length of curve, superelevation, the number of lanes, grade variations, and the approaching free-flow speed on 100 m upstream of PC. Tests showed that the free-flow speeds estimated by the proposed model were statistically identical to the ones from the field at 95% confidence level at each three different locations described above. The root mean square errors at the starting and the middle of curve section were 6.68 and 10.06, and the R-squares at these points were 0.77 and 0.65, respectively. It was concluded from the study that the proposed model would be one of the potential tools introducing the effects of highway design elements to free-flow speeds in simulation.