• Electrical & Electronic Materials
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• v.8 no.3
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• pp.324-331
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• 1995

0.36[wt%l $SiO_{2}$ and 0.1[wt%] $H_{3}$B $O_{3}$ were added to strontium ferrite magnets of the magnetoplumbite phase SrO.5.7F $e_{2}$ $O_{3}$ to hinder grain growth and accelerate sintering, respectively. This experiment was carried out to investigate effect of particle size distribution as a function of milling time(20, 30, 40, 50, 60, 70 hours) on the magnetic properties of SrO.5.7F $e_{2}$ $O_{3}$ ferrite magnet. The B-H curve, density and the degree of orientation were measured. And the microstructure of ferrite magnets was examined with a SEM. The optimal conditions and properties of the typical sample are the following : The milling time was 60 hours. Magnetic and physical properties are $B_{r}$=4, 000[G], $_{b}$ $H_{c}$=3, 330[Oe], (BH)max=3.786[MGOe], $_{I}$ $H_{c}$=3, 525[Oe], density=5.0063[g/c $m^{3}$] and orientation factor f=0.813.0.813.3.3.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.2
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• pp.124-129
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• 2016

Endotoxin, also known as lipopolysaccharide (LPS) produced by the cell wall of gram negative bacteria can be present in any liquid or on any biomaterial. Endotoxin in blood can cause fever and inflammation. In this study, we compared bacterial endotoxin using Escherichia coli O157:H7, Klebsiella oxytoca, Salmonella Typhi, Shigella sonnei and Morganella morganii. Bacteria were cultured for use in the experiment, and diluted to $1.5{\times}10^8CFU/mL$. A check marked sensitivity confirmatory test of the Limulus amebocyte lysate (LAL) reagent was performed to examine the validity. The end point reaction to each bacteria sample was confirmed with 10 fold dilution and then the final reaction end point was confirmed by 2 fold dilution between the dilution step and the upper dilution step. According to the results, in detection of endotoxins in more than 0.015 EU/mL, E. coli O157 was 75~37.5 CFU/mL, K. oxytoca 37.5~18.75 CFU/mL, M. morganii and S. Typhi 3.75~1.875 CFU/mL, and S. sonnei 7.5~3.75 CFU/mL. The resulting value was finally ensured by a confirmation test for the inhibitory factor. Based on this study, conduct of further research on bacterial endotoxin is encouraged.

• BMB Reports
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• v.36 no.4
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• pp.373-378
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• 2003

Effects of L-arginine and NG-nitro-L-arginine methyl ester (L-NAME) on the renal dysfunction that is induced by cisplatin (CDDP) were investigated. A single dose of CDDP (7.5 mg/kg i.p.) induced renotoxicity, which was manifested by increasing the sensitivity of isolated urinary bladder rings to acetylcholine (ACh), together with a significant elevation of serum urea and creatinine, and a severe decrease in serum albumin. Moreover, renal dysfunction was further confirmed by a significant decrease of enzyme activities, such as glutathione peroxidase, GSH-Px (E.C 1.11.1.9), catalase (E.C 1.11.1.6), as well as a significant increase in lipid peroxides that were measured as malondialdhyde (MDA) in kidney tissue homogenates. The administration of L-arginine (70 mg/kg/d p.o in drinking water 5 d before and 5 d after the CDDP injection) significantly ameliorated the renotoxic effects of CDDP, as judged by restoring the normal responses of isolated bladder rings to Ach, and also by an improvement in a range of renal function indices, which included serum urea and creatinine concentrations and kidney weight. In addition, L-arginine prevents the rise of MDA, as well as a reduction of GSH-Px and catalase activities in kidney tissues homogenates. On the other hand, the administration of L-NAME (4 mg/kg/d p.o) resulted in no protection against renal dysfunction that was induced by CDDP treatment. The findings of this study suggest that L-arginine can attenuate kidney injury that is produced by CDDP treatment. In addition, L-arginine may be a beneficial remedy for CDDP-induced renal toxicity, and could be used to improve the therapeutic index of CDDP.

• Journal of Magnetics
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• v.14 no.2
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• pp.62-65
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• 2009

The multiferroic $BiFeO_3$ has been investigated extensively in both thin film and ceramic form. However, the synthesis of a perfect sample with high resistivity is a prerequisite for examining its properties. This paper reports the synthesis of multiferroic $BiFeO_3$ along with its structural, electrical and magnetic properties in ceramic form. Polycrystalline ceramic samples of $BiFeO_3$ were synthesized by solid-state reaction using high purity oxides and carbonates. The formation of a single-phase compound was confirmed by x-ray diffraction and its lattice parameters were determined using a standard computer program. The microstructural studies and density measurement confirmed that the prepared samples were sufficiently dense for an examination of its electrical and magnetic properties. The dc electrical conductivity studies show that the sample was resistive with an activation energy of ${\sim}0.81\;eV$. The magnetization measurement showed a linear ($M{\sim}H$) curve indicating antiferromagnetic characteristics.

• Journal of Plant Biotechnology
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• v.2 no.1
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• pp.35-41
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• 2000

Transgenic cabbage (Brassica oleracea ssp. capitata) plants resistant to the commercial herbicide Bast $a^{R}$ were obtained by Agrobacterium tumefaciens - mediated transformation. Hypocotyl segments of in vitro grown plants were infected with Agrobacterium tumefaciens LBA 4404 harboring plasmid pMOG6-Bar which contains hpt and bar genes. Explants were cultured on callus induction medium (MS basal medium + 1 mg/L NAA + 2 mg/L BA + 2 mg/L AgN $O_3$+ 100 mg/L carbenicillin + 250 mg/L cefotaxime) supplemented with 15 mg/L hygromycin. Hygromycin resistant calluses were transferred to shoot regeneration medium (MS basal medium + 0.1 mg/L NAA + 2 mg/L BA + 3% sucrose + 2 mg/L AgN $O_3$+ 15 mg/L hygromycin + 250 mg/L cefotaxime + 100 mg/L carbenicillin). In order to induce roots, elongated shoots were placed on the MS medium without plant growth regulators and hygromycin. Southern blot analysis of several putative transgenic plants indicated that one to five intact copies of Apt and bar genes were incorporated into the genome. Expression of bar gene was confirmed by Northern blot analysis and by herbicide resistant phenotype. Seed progeny from self-pollinated transformants expressed the herbicide resistance and showed Mendelian segregation of the introduced gene.e.

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.147-153
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• 2004

Protein modification by N-acetyl-${\beta}$-D-glucosamine (O-G1cNAc) on the hydroxyl groups of Ser or Thr ubiq-uitously occurs in eukaryotic cells and is involved in many cellular phenomena. The level of O-G1cNAc-mod-ified protein is regulated by OGT and O-GlcNAcase enzymes. We have tried to produce recombinant O-GlcNAcase in E. coli as an effort to establish in vitro screening system for modulators of O-GlcNAcase. The culture conditions for improvement of O-GlcNAcase productivity, were as follows: induction temperature, $30^{\circ}C$; the concentration of L-arabinose, 0.02% and induction time, 5 hr. Under these culture conditions, E. coli cells containing O-GlcNAcase gene had no enzyme activity until up to 3 hr culture. However, O-GlcNAcase activity dramatically increased from 3 to 5 hr culture. It almost maintained the same level after 5 hr culture. Western blot analysis verified the amount of expressed O-GlcNAcase increased with culture time, being con-sistent with activity data. The optimal reaction condition determined in this study was as follows: protein quan-tity, $5{\mu}g$; reaction time, 30 min; reaction temperature, $45^{\circ}C$; substrate concentration, 2 mM; reaction pH, 6.5. Methanol had little effect on O-GlcNAcase activity and 90% of activity were retained at 10%. Only 15% resid-ual activity were detected at 5% of chloroform.

• The Journal of the Korean Society for Microbiology
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• v.18 no.1
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• pp.53-58
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• 1983

Enterotoxigenic E. coli is one of causative agents of the infantile diarrhea and traveler's diarrhea. A modified infant mouse assay(IMA) was developed for the detection of heat stable enterotoxin (ST) of E. coli isolated from diarrheal and control infants and assay system was established with using enterotoxin producing reference strains. The supernatant of the 24 hour-shaking culture of E. coli in Casamino Acid Yeast Extract Salt Broth(CYES-2) was ingested orally into the 2-4 day old ICR mice. After the mice were kept at $25^{\circ}C$ for 4 hours, they were sacrificed and the gut weight body weight ratio(GW/BW) was taken as the index of fluid accumulation induced by heat stable enterotoxin of E. coli. The results obtained were as follows; 1. The GW/BW responses of IMA tested with enterotoxin reference strains of E. coli(E. coli O148H28:$ST^+LT^+$, E. coli $O78H^-:ST^+LT^+$, E. coli O15H11:$ST^-LT^+$, E. coli O1H7:$ST^-LT^-$) appeared ta be ST dose-dependent, and not LT-dependent. From the dose-response curve, $25{\mu}l$ of culture supernatant was determined as test amount of the IMA. 2. Frequency distribution of IMA result from 643 strain of E. coli showed normal distribution at low GW/BW ratio and dispersed pattern at high GW/BW ratio. The GW/BW ratios of $0.056{\pm}0.004(mean{\pm}SD)$ of normal distribution which distributed from 0.044 to 0.068(P<0.01) was considered as ST negative. Thus the GW/BW ratio above 0.069 could be regarded as ST positive.

• Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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• v.9
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• pp.1-21
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• 2004

Die sogenannten verba pura bilden eine Teilmenge der germanischen starken Verben der VII. KLasse. Sie sind auf einsilbige langvokalisch auslautende Wurzeln des Vorurgermanischen $zur\"{u}ckzufuhren$: z. B. ${\ast}kn\bar{e}an$ 'erkennen', ${\ast}m\bar{e}an$ '$m\"{a}hen$', ${\ast}bl\bar{o}an$ $'bl\"{u}hen'$, ${\ast}m\bar{o}an$ $'qu\"{a}hlen'$. Um den Begriff der verba pura genau zu $erkl\"{a}ren$, stellt man diesen Verben die sogenannten verba impura $gegen\"{u}ber$, bei denen auf die lang Wurzelvokale urgerm. ${\ast}-\bar{e}-$ und ${\ast}-\ber{o}-$ ein Konsonant folgl: z.. B. urgerm. ${\ast}l\bar{e}tan$ (got. \etan) 'lassen', ${\ast}hw\bar{o}pan$ (got. hvopan) 'sich $r\"{u}hmen$'. Die germanischen starken Verben der VII. Klasse hat die $st\"{a}rksten$ Umgestaltungen mitgemacht, und zwar die verba pura noch mehr. In diesem Aufsatz untersuchte ich die $Gr\"{u}nde$ ihrer Umgestaltungen im germanischen Verbalsystem. Danach wird der Vorgang erschlossen, wie die verba pura in Ahd. zu den schwachen Verben I $\"{u}bertraten$. Dabei werden die folgenden Punkte besonders behandelt: Hatten die $fr\"{u}hzeitigen${\;}Pr\"{a}sensformen$ der verba pura -i-, das aus -jan herausgeht? Wenn nein, wie haben die verba pura zur schwachen Flexion $\"{u}bertraten$? Warum konnten die verba pura wie die anderen redupliziernden Verben in Ahd. nicht zu ablautenden Verben $\"{u}bergehen$?

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.3
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• pp.522-523
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• 1989

• Korean Journal of Microbiology
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• v.30 no.3
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• pp.225-231
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• 1992

l o identil) ;~nclc li~iracterize; In iiscorhate oxiililinp enzyme in ('/rItrn~i~rlon~ir~c~t~itr~~lr.o\ r(1rii. we studicil ;is li)llows. Ascorh;ric oxiiliring cn/;jme activit) f ~ o ~thne crude extract 01' ( ' / ~ l o n ~ ~ . c l o t ~1~~oit~rl~1oin~/.t\ii W;I\ dctccietl by 5pecific active 5ta1ning through nati\e gel cletrophorcsi\ and ~iltra\~iolestp eciroscopy. Ascorb~ttco xidizing c n ~ y m ew i15 partilly 1~1rilieJ by \;~riousp roccclurcs inclucli~lga rnmoniu~ns uIl';~tcp recipit;iion. aJ\orption ~111-om;~togrophy on Iiy~lroxyapaiitca nd Scphailcx <;-I50 gel lillration chrornatogral>liy. Plie ~nolecularw eight 01' the nativc cnrytiic was ahour 88.000 tlalton hy nativc gel elcciroplloresis anci subunit niolecul;ir ~rciglit 55,000 ol' this cnrymc w;~c determined hy SIIS-P.ASI!. The optimum tcmper~tture ii)r the cnrymc nos ahout 5j$^{\circ}$C and pH 4.6 was the optimum. Moreover. ascorhaie oxi~losc in C: reinhardtii was confirmet1 by Ll1e\tcrn blotting technique.