• Korean Journal of Veterinary Research
• /
• v.36 no.2
• /
• pp.379-387
• /
• 1996

The objects of the present study were to establish the method of purification, subunit dissociation of verotoxin-2 (VT2) produced by Escherichia coli O157:H7, and to investigate the characteristics of purified verotoxin-2 such as molecular weight and composition of amino acid. The results were summerized as follows; Verotoxin-2 was extracted by addition of polymyxin B sulfate into bacterial cell lysate prepared from Escherichia coli O157:H7(KSC109). As an initial step, the bacterial cell lysate was precipitated with 30% saturated ammonium sulfate. The precipitated crude toxin was then subjected to anion-exchange, chromatofocusing and cation-exchange chromatography. Using this scheme, we obtained highly purified toxin with a specific activity of $1.1{\times}10^9$ $CD_{50}/mg$. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) for purified VT2 showed two protein bands. The upper band, approximately 32 Kd, was supposed as A subunit and the lower band, approximately 7.7 Kd, was supposed as B subunit. When the toxin was separated in the subunit-dissociating solution, two peaks emerged with retention times of 15 and 28 min by HPLC. These peaks represented A subunit and B subunit, respectively. The amino acid composition of purified VT2 were made up in order of glutamic acid, histamine, asparaginic acid, histidine, lysine, alanine and leucine etc. The largest amount among the amino acid composing VT2 was methionine.

• The Korean Journal of Emergency Medical Services
• /
• v.7 no.1
• /
• pp.109-118
• /
• 2003

With the rapid development of information and communication technology, a lot of multi-media learning programs are being developed and reported in the field of Emergency medicine both home and abroad. In this connection, this study was aimed at developing a foreign-body airway obstruction courseware in adults for EMT. The development period of CAI courseware lasted from May 2003 through November 2003. Among CAI courseware patterns, private instruction and repeat practice and simulation patterns were used as an instruction-learning strategy. The learning contents of the CAI courseware consisted of five chapters concerning (1) A relief of partial FBAO in the responsible victim, (2) A relief of complete FBAO in the responsible victim, (3) In case of unconsciousness in the responsible victim without removing all foreign body, (4) In case of consciousness in all victims after getting removed all foreign body and (5) A complete airway obstruction in victims without consciousness on the basis of assess responsiveness and the degree of airway obstruction. The way to use this courseware, with just a click on one specific chapter, was developed to proceed a course with progressive algorithm, a method of solving problems by choosing one between two situations. A characteristic of this CAI courseware is the enhanced efficiency of an instruction-learning method by providing an opportunity of choice based on situations in its effort to encourage learners to use a self-initiated learning method, not one-way method and to enhance problem solving skills among situations. Moreover, this courseware went through the diverse phases such as development, application, feedback in connection with learning process by practicing teachers, so that the courseware could be used frequently in the future. The contents of this courseware were written with the web, so that, if necessary, the contents could be continuously modified and complemented and handed out in the form of CD-ROM. This study indicates that the development of a variety of CAI courseware requires institutional and financial assistance and initiatives reflecting a reality in terms of learning process, technical assistance and resources.

• Journal of the Korean Magnetic Resonance Society
• /
• v.11 no.2
• /
• pp.95-109
• /
• 2007

Vanadium-incorporated aluminophosphate microporous molecular sieve VH-SAPO-42 has been studied by electron spin resonance(ESR) and electron spin-echo modulation (ESEM) spectroscopies to determine the vanadium location and interaction with various adsorbate molecules. The results are interpreted in terms of V(IV) ion location and coordination geometry. Assynthesized VH-SAPO-42 contains only vanadyl species with distorted octahedral or trigonal bipyramidal coordination. Vanadium incorporated into H-SAPO-42 occupied extra-framework site. After calcinations in $O_2$ and exposure to moisture, only species A is observed with reduced intensities. Species A is identified as a $VO(H_2O)_2^{2+}$ complex coordinated to three framework oxygen atoms bonded to aluminum. When hydrated VH-SAPO-42 is dehydrated at elevated temperature by calcination, species A loses its water ligand and transforms to $VO^{2+}$ ions coordinated to three framework oxygens (species B). Species B reduces its intensities significantly after treatment with $O_2$ at high temperature, thus suggesting oxidation of $V^{4+}$ to $V^{5+}$. When dehydrated VH-SAPO-42 makes contact with $D_2O$ at room temperature, the ESR signal of species A is regained. The species is assumed as a $VO(O_f)_3(D_2O)_2$ by considering three framework oxygens. Adsorption of deuterated methanol on dehydrated VH-SAPO-42 results in another new vanadium species D, which is identified as a $VO(CD_3OH)_2$ complex. When deuterated ethylene is adsorbed on dehydrated VH-SAPO-42, another new vanadium species E identified as a $VO(C_2D_4)^{2+}$, is observed. Possible coordination geometries of these various complexes are discussed.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.19 no.6
• /
• pp.1585-1593
• /
• 2005

The genetic effects of restraint stress challenge on HPA axis and the therapeutic effect of Boshimgeonbi-tang on the stress were studied with cDNA microarray analyses, RT-PCR on hypothalamus using an immobilization-stress mice as an animal model. Male CD-1 mice were restrained in a tightly fitted and ventilated vinyl holder for 2hrs once a day, and this challenge was repeated for seven· consecutive days. In the change of body weight it showed that the Boshimgeonbi-tang is effected recovery on weight loss caused by the immobilization-stress. Seven days later, total RNA was extracted from the organs of the mouse, body-labeled with $CyDye^{TM}$ fluorescence dyes and then hybridized to CDNA microarray chip. Scanning and analyzing the array slides were carried out using GenePix4000 series scanner and GenePix $Pro^{TM}$ analyzing program, respectively. The expression profiles of 109 genes out of 6000 genes on the chip were significantly modulated in hypothalamus by the immobilization stress. Energy metabolism-, lipid metabolism-, apoptosis-, stress protein, transcriptional factor, and signal transduction-related genes were transcriptionally activated whereas DNA repair-, protein biosysthesis-, and structure integrity-related genes were down-regulated in hypothalamus. The 58 genes were up-regulated by the mRNA expression folds of 1.5 to 7.9. and the 51 genes were down-regulated by 1.5 - 5.5 fold. The 11 genes among them were selected to confirm the expression profiles by RT-PCR. The mRNA expression levels of Tnfrsf1a (apoptosis), Calm2 (cell cycle), Bag3 (apoptosis), Ogg1 (DNA repair), Aatk (apoptosis), Dffa (apoptosis), Fkbp5 (protein folding) were restored to the normal one by the treatment of Boshimgeonbi-tang.

• Nuclear Engineering and Technology
• /
• v.34 no.6
• /
• pp.545-552
• /
• 2002

We developed an ultra low background gamma ray spectrometer particularly suitable for experiment which require lower detection limit. The background of a germanium spectrometer is suppressed by applying active and passive shielding technique at the same time. The active shielding devices consist of plastic scintillating plates of 50 mm thick and anti-coincidence electronic system. The shielding is made of 150 mm thick walls of very low activity lead,20 mm with activity of <10 Bq/kg and 130 mm with activity of <50 Bq/kg. The observed background count rates are 1.2 $s^{-1}$ and 0.36 $s^{-1}$ without and with the active shielding, respectively, overall the energy regions from 30 keV to 3 MeV The cosmic ray induced background is suppressed by a rate of 0.8 $s^{-1}$ at the present work. The detection efficiency curve necessary to obtain the radioactivity of environmental samples has been precisely determined on the energy regions from 80 to 2000 keV with a 10$^3$ ml marinelli beaker sample, consisting of the calibrated radionuclides $^{109}$ Cd, $^{57}$ CO, $^{139}$ Ce, $^{203}$ Hg, $^{113}$ Sn, $^{85}$Sr, $^{137}$ Cs, $^{60}$ Co and $^{88}$ Y. Virtues Of the method are demonstrated by measuring the activity of $^{137}$ Cs contained in the powdered milk.

• The Korean Journal of Ecology
• /
• v.18 no.1
• /
• pp.109-120
• /
• 1995

As the genetically modified microorganisms (GMMs) and their recombinant plasmid DNAs could be released into natural environments, their stabilities and impacts to indigenous microorganisls have become very importhant research subjects concerning with environmental and ecological aspects. In this study, the genetically modified E. coli CU103 and its recombinant pCU103 plasmid DNA, in which pcbCD genes involving in degradation of biphenyl and 4-chlorobiphenyl were cloned, were studied for their survival and stability in several different waters established under laboratory conditions. E. coli CU103 and its host E. coli XL1-Blue survived longer in sterile distilled water (SDW) and filtered autoclaved river water (FAW) than in filtered river water (FW). A lot of extracellular DNAs were released from E. coli CU103 by lytic action of phages in FW and the released DNAs were degraded by DNase dissolved in the water. Such effects of the factors in FW on stability of the recombinant pCU103 plasmid were also observed in the results of gel electrophoresis, quantitative analysis with bisbenzimide, and transformation assay. Therefore, the recombinant plasmids of pCU103 were found to be readily liberated from the genetically modified E. coli CU103 into waters by normal metabolic processes and lysis of cells. And the plasmid DNAs were quite stable in waters, but their stabilities could be affected by physicoKDICical and biological factors in non-sterile natural waters.

• BMB Reports
• /
• v.37 no.4
• /
• pp.408-415
• /
• 2004

The expression of the Paenibacillus sp. A11 cyclodextrinase (CDase) gene using the pUC 18 vector in Escherichia coli JM 109 resulted in the formation of an insoluble CDase protein in the cell debris in addition to a soluble CDase protein in the cytoplasm. Unlike the expression in Paenibacillus sp. A11, CDase was primarily observed in cytoplasm. However, by adding 0.5 M sorbitol as an osmolyte, the formation of insoluble CDase was prevented while a three-fold increase in cytoplasmic CDase activity was achieved after a 24 h-induction. The recombinant CDase protein was purified to approximately 14-fold with a 31% recovery to a specific activity of 141 units/mg protein by 40-60% ammonium sulfate precipitation, DEAE-Toyopearl 650 M, and Phenyl Sepharose CL-4B chromatography. It was homogeneous by non-denaturing and SDS-PAGE. The enzyme was a single polypeptide with a molecular weight of 80 kDa, as determined by gel filtration and SDS-PAGE. It showed the highest activity at pH 7.0 and $40^{\circ}C$. The catalytic efficiency ($k_{cat}/K_m$) values for $\alpha$-, $\beta$-, and $\gamma$-CD were $3.0{\times}10^5$, $8.8{\times}10^5$, and $5.5{\times}10^5\;M^{-1}\;min^{-1}$, respectively. The enzyme hydrolyzed CDs and linear maltooligosaccharides to yield maltose and glucose with less amounts of maltotriose and maltotetraose. The rates of hydrolysis for polysaccharides, soluble starch, and pullulan were very low. The cloned CDase was strongly inactivated by N-bromosuccinimide and diethylpyrocarbonate, but activated by dithiothreitol. A comparison of the biochemical properties of the CDases from Paenibacillus sp. A11 and E. coli transformant (pJK 555) indicates that they were almost identical.

• Journal of Environmental Health Sciences
• /
• v.26 no.2
• /
• pp.22-29
• /
• 2000

This study was performed to investigate the concentrations of TSP, PM10 and heavy metals(Pb, Cd,Hg, Ni, Zn) of underground parking lots in Taegu city. The samples were collected from 3 department stores and 1 central park in the winter and the summer, 1997. The samples of 3 department stores were divided into sale period and non-sale period in the winter and the summer. The concentrations of TSP and PM10 were 109.6±1.5㎍/㎥ and 93.3±1.5㎍/㎥. In TSP, the zinc was the highest level, 287.16±1.5ng/㎥ and the cadmium was the lowest, 2.4±2.1ng/㎥ and in PM10, the zinc was the highest level, 193.6±1.5ng/㎥ and the cadmium was the lowest, 0.6±3.9ng/㎥. The correlation coefficient between the concentration of TSP and PM10 was 0.982(p<0.05). The correlation coefficients of corresponding heavy metal in TSP and PM10 were 0.863 for lead, 0.617 for mercury, 0.890 for nickel and 0.850 for zinc(p<0.05). The concentrations of TSP, PM10 and cadmium of PM10 in the winter were higher than those of the summer. However, the concentration of Hg of PM10 in the summer was higher than that of the winter. The concentrations of TSP and PM10 in sale period was higher than those of non-sale period and the concentrations of heavy metal in TSP and PM10 were not significantly different between sale and non-sale period. The proportions of PM10 to TSP were above 60% in dust, lead, nickel, and zinc and less than 40% in cadmium and mercury. The concentrations of TSP, PM10 and heavy metal in the underground parking lots were comparatively lower than those of general atmosphere. However, this kind of research to PM10 in the underground parking lots must be continued because it is very important particulate matter that affects human beng's health.

• Korean Journal of Soil Science and Fertilizer
• /
• v.33 no.2
• /
• pp.109-113
• /
• 2000

The purpose of this study was conducted to develop the slow-released N fertilizer(SRNF) using of waste paper cellulose. Properties of trial product was investigated. Contents of nitrogen, phosphorus, and potassium in trial product were showed 26%, 0.04 and 0.01%, respectively. The contents of Cr, Cu, Pb and Zn were showed 17.4ppm. 259ppm, 12.2ppm and 60.0ppm in the trial product, respectively. However, As and Cd was not detected. Nitrogen of SRNF could be released 60.4% within 12hr after dissolution in water. However, the releasing velocity was thereafter remarkably delayed, showing 75% after dissolution for 72hr.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.15 no.2
• /
• pp.109-117
• /
• 2013

The Global Framework on Climate Services (GFCS) will guide the development of climate services that link science-based climate information and predictions with climate-risk management and adaptation to climate change. GFCS structure is made up of 5 pillars; Observations/Monitoring (OBS), Research/ Modeling/ Prediction (RES), Climate Services Information System (CSIS) and User Interface Platform (UIP) which are all supplemented with Capacity Development (CD). Corresponding to each GFCS pillar, the Commission for Agricultural Meteorology (CAgM) has been proposing "Global Initiatives in AgroMeteorology" (GIAM) in order to facilitate GFCS implementation scheme from the perspective of AgroMeteorology - Global AgroMeteorological Outlook System (GAMOS) for OBS, Global AgroMeteorological Pilot Projects (GAMPP) for RES, Global Federation of AgroMeteorological Society (GFAMS) for UIP/RES, WAMIS next phase for CSIS/UIP, and Global Centers of Research and Excellence in AgroMeteorology (GCREAM) for CD, through which next generation experts will be brought up as virtuous cycle for human resource procurements. The World AgroMeteorological Information Service (WAMIS) is a dedicated web server in which agrometeorological bulletins and advisories from members are placed. CAgM is about to extend its service into a Grid portal to share computer resources, information and human resources with user communities as a part of GFCS. To facilitate ICT resources sharing, a specialized or dedicated Data Center or Production Center (DCPC) of WMO Information System for WAMIS is under implementation by Korea Meteorological Administration. CAgM will provide land surface information to support LDAS (Land Data Assimilation System) of next generation Earth System as an information provider. The International Society for Agricultural Meteorology (INSAM) is an Internet market place for agrometeorologists. In an effort to strengthen INSAM as UIP for research community in AgroMeteorology, it was proposed by CAgM to establish Global Federation of AgroMeteorological Society (GFAMS). CAgM will try to encourage the next generation agrometeorological experts through Global Center of Excellence in Research and Education in AgroMeteorology (GCREAM) including graduate programmes under the framework of GENRI as a governing hub of Global Initiatives in AgroMeteorology (GIAM of CAgM). It would be coordinated under the framework of GENRI as a governing hub for all global initiatives such as GFAMS, GAMPP, GAPON including WAMIS II, primarily targeting on GFCS implementations.