• Journal of The Korean Astronomical Society
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• v.38 no.2
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• pp.283-287
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• 2005

The slow evolution of global magnetic fields and other dynamical processes in atmospheres of CP magnetic stars lead to the development of induced electric currents in all conductive atmospheric layers. The Lorentz force, which results from the interaction between a magnetic field and the induced currents, may modify the atmospheric structure and provide insight into the formation and evolution of stellar magnetic fields. This modification of the pressure-temperature structure influences the formation of absorption spectral features producing characteristic rotational variability of some spectral lines, especially the Balmer lines (Valyavin et al., 2004 and references therein). In order to study these theoretical predictions we began systematic spectroscopic survey of Balmer line variability in spectra of brightest CP magnetic stars. Here we present the first results of the program. A0p star $\Theta$ Aur revealed significant variability of the Balmer profiles during the star's rotation. Character of this variablity corresponds to that classified by Kroll (1989) as a result of an impact of significant Lorentz force. From the obtained data we estimate that amplitudes of the variation at H$\alpha$, H$\beta$, H$\gamma$ and H$\delta$ profiles reach up to $2.4\%$during full rotation cycle of the star. Using computation of our model atmospheres (Valyavin et al., 2004) we interpret these data within the framework of the simplest model of the evolution of global magnetic fields in chemically peculiar stars. Assuming that the field is represented by a dipole, we estimate the characteristic e.m.f. induced by the field decay electric current (and the Lorentz force as the result) on the order of $E {\~} 10^{-11}$ cgs units, which may indicate very fast (< < $10^{10}$ years) evolution rate of the field. This result strongly contradicts the theoretical point of view that global stellar magnetic fields of CP stars are fossil and their the characteristic decay time of about $10^{10}$ yr. Alternatively, we briefly discuss concurring effects (like the ambipolar diffusion) which may also lead to significant atmospheric currents producing the observable Lorentz force.

• KSBB Journal
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• v.11 no.4
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• pp.411-419
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• 1996

In this research, an extractive production system for alkaloids, where production and some degree of separation occur simultaneously, was developed in a way that the fast removal of alkaloid produced from the suspension cultures was done by capturing alkaloid with cyclodextrins. The alkaloid production was substantially enhanced up to 40 fold when the solid cultures of E. califonica cells treated with ${\beta}$-cyclodextrin compared to the control. The enhancement of alkaloid production was also observed in the suspension cultures. Interestingly, the production pattern seemed to change when the cultures were treated with ${\beta}$-cyclodextrin so that the major part of the alkaloids in the treated cultures was present in the medium, while the non-treated cultures produced the alkaloids intracellularly. ${\beta}$-cyclodextrin was the most effective one in terms of the alkaloid production among the cyclodextrilns(${\alpha}$-cylodextrin, ${\beta}$-cyclodextrin and ${\gamma}$-cyclodextrin) tested in the suspension cultures. ${\beta}$-cyclodextrin showed no adverse effect on the cell growth. The most effective concentration of ${\beta}$-cyclodextrin was observed around 1.5% (w/v) in the suspension cultures. The formation of the inclusion complex of the alkaloids with ${\beta}$-cyclodextrin in the suspension cultures was confirmed by detecting the shift of UV absorbance from 274 nm to 282 nm with a UV spectrophotometer.

• Korean Journal of Materials Research
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• v.13 no.6
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• pp.347-351
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• 2003

II-Ⅵ ZnO compound semiconductor thin films were grown on $\alpha$-Al$_2$O$_3$(0001) single crystal substrate by radical beam assisted molecular beam epitaxy and the optical properties were investigated. Zn(6N) was evaporated using Knudsen cell and O radical was assisted at the partial pressure of 1$\times$10$^{4}$ Torr and radical beam source of 250-450 W RF power. In $\theta$-2$\theta$ x-ray diffraction analysis, ZnO thin film with 500 nm thickness showed only ZnO(0002)and ZnO(0004) peaks is believed to be well grown along c-axis orientation. Photoluminescence (PL) measurement using He-Cd ($\lambda$=325 nm) laser is obtained in the temperature range of 9 K-300 K. At 9 K and 300 K, only near band edge (NBE) is observed and the FWHM's of PL peak of the ZnO deposited at 450 RF power are 45 meV and 145 meV respectively. From no observation of any weak deep level peak even at room temperature PL, the ZnO grains are regarded to contain very low defect density and impurity to cause the deep-level defects. The peak position of free exciton showed slightly red-shift as temperature was increased, and from this result the binding energy of free exciton can be experimentally determined as much as $58\pm$0.5 meV, which is very closed to that of ZnO bulk. By van der Pauw 4-point probe measurement, the grown ZnO is proved to be n-type with the electron concentration($n_{e}$ ) $1.69$\times$10^{18}$$cm^3$, mobility($\mu$) $-12.3\textrm{cm}^2$/Vㆍs, and resistivity($\rho$) 0.30 $\Omega$$\cdot$cm.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1405-1411
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• 2006

The presence and content of residual hexane in the olive oils were studied. Total 41 olive oils of imported and domestic brands, which were labeled as extra virgin and refined (mixed), were collected from the market. For analysis, electronic nose and headspace SPME-GC/MS were used. Electronic nose equipped with 12 metal oxide sensors was used for the discrimination of odor pattern of olive oils against the different concentrations of hexane. From the results, it is assumed that the contents of residual hexane in the collected olive oils were below 5 ppm. For Qualitative and quantitative analysis of hexane, polydimethylsiloxane (PDMS) fiber was employed for SPME-GC/MS. In the results, the peak of residual hexane was detected in 8 samples from 41 olive oils. But the detected level was no more than 1 ppm that is under the regulation limit (5 ppm) by Korea Food Additive Code.

• Journal of Life Science
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• v.19 no.7
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• pp.845-851
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• 2009

A vector harboring double cassettes; a heterologous gene expression cassette of pHCE-InaN-antigen and a ghost formation cassette of pAPR-cI-E lysis 37 SDM was constructed and introduced to E. coli DH5a. For the production of a bacterial ghost vaccine, bacterial ghosts from E. coli / Streptococcus iniae with four different types of antigens - enolase, GAPDH, sagA and piaA - were produced by the optimization of fermentation parameters such as a glucose concentration of 1 g/l, agitation of 300 rpm and aeration of 1 vvm. Efficiency of ghost bacteria formation was evaluated with cultures of OD$_{600}$=1.0, 2.0 and 3.0. The efficiency of the ghost bacteria formation was 99.54, 99.67, 99.99 and 99.99% with inductions at OD$_{600}$=3.0, 1.0, 2.0 and 1.0 for E. coli/S. iniae antigens enolase, piaA, GAPDH and sagA, respectively. Ghost bacteria as a vaccine was harvested by centrifugation. The antigen protein expressions were analyzed by SDS-PAGE and western blot analysis, and the molecular weights of the enolase, piaA, GAPDH and sagA were 78, 26, 67 and 26 kDa, respectively. The molecular weights of the expressed antigens were consistent with theoretical sizes obtained from the amino acid sequences.

• Parasites, Hosts and Diseases
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• v.26 no.2
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• pp.95-106
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• 1988

Specific or non-specific cytolytic processes of free-living amoebae causing meningoencephalitls have been emphasized and the cytolytic ability related to hydrolases in Entantoeba sp. and Naegleria sp. has also been reported since the latter half of 1970's. However, no information on hydrolase activities in Acanthamoeba sp. is available. Hydrolases in Acanthamoeba culbertsoni, a pathogenic species of free-living amoebae, were assayed and compared with those in a non-pathogenic species, A. royreba. Pathogenicity of these two species was confirmed through experimental infection to BALB/c mice. Hydrolase activities and cytotoxic effects between pathogenic and non.pathogenic species were compared in the trophozoites cultured in CGV media and in CHO cell line, respectively. The results are summarized as follows: 1. The mice infected with A. culbertseni were all dead 15 days after nasal inoculation, and the mean survival time was 8.5 days. Also the mice infected with this pathogenic species manifested typical meningoencephalitis, whereas the mice infected with A. royreba did not. 2. Hydrolases detected both in the cell extracts and culture media were acid phosphatase, ${\beta}-N-acetyl$ galactosaminidase, ${\beta}-N-acetyl$ glucosaminidase, ${\alpha}-mannosidase$, neutral proteinase and acid proteinase, all of which were detected with remarkably higher rate in A. culbertsoni than in A. royreba. 3. A. cuzbertsoni revealed strong cytotoxicity for the target CHO cells, whereas A. royreba did not show any specific cytotoxicity. About 80% of the target cells mixed with A. culbertsoni were dead 48 hours after cultivation, and more than 95% of the target cells were dead 72 hours after cultivation. 4. Hydrolase activities in A. culbertsoni cultured with the target cell line were assayed according to the culture time. The activities of acid phosphatase, ${\beta}-N-acetyl$ galactosaminidase, ${\beta}-N-acetyl$ glucosaminidase, ${\alpha}-mannosidase$ and acid proteinase in this pathogenic amoeba were detected higher in amoeba extracts than in culture media up to 120 hours after cultivation, but after 120 hours of cultivation those activities were detected higher in culture media than in the amoeba Iysates. Neutral proteinase activity in A. culbertsoni increased more in EBSS medium than in the Iysate specimens although the activity in the extracts was generally steady according to the cultivation time. Summarizing the above results, it is concluded that there were differences in hydrolase activities between Pathogenic A. culbertsoni and non-pathogenic A. royreba, and that some hydrolase activities were detected remarkably higher in A. culbertsoni which revealed strong cytotoxicity to the target CHO cell line.

• KSBB Journal
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• v.24 no.6
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• pp.549-555
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• 2009

4 kinds of Regional Special Natural Products (RSNPs), such as Anthrisci radix, Psoraleae semen, Siegesbeckiae herba and Corni fructus were examined to verify for anti-obesity effect. $PPAR\gamma$ (peroxisome proliferator-activated receptor $\gamma$) from 3T3-L1 cell concerning adipocyte differentiation was suppressed by different concentraton of 4 RSNPs with western blot, when treated RSNPs' extract and MDI (IBMX, Dexamethasone, Insulin) at the same time. Also, SREBP-1 (Sterol regulatory element binding protein) controlling lipogenesis and $PPAR\gamma$ expression levels were reduced by these 4 RSNPs' extract, when these chemicals after differentiation of 3T3-L1 cell. And lipid droplets were reduced by 7.5%, 14.4%, 18.3% and 30% at different concentration of Anthrisci radix from Oil Red O staining. Also, it was reduced by 2%, 4.9%, 9.3% and 38% at different concentration of Psoraleae semen. For Siegesbeckiae herba, it was inhibited by 1.4%, 6.4%, 16.4% and 30.1%, respectively. And Corni fructus was also showed by 0.9%, 6.3%, 13.7% and 33% at same concentration of Siegesbeckiae herba. These 4 kinds of RSNPs were expected for a useful material for anti-obesity materials.

• Korean Journal of Pharmacognosy
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• v.40 no.4
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• pp.370-375
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• 2009

Overproduction of peroxynitrite ($ONOO^-$) causes a variety of disease such as atherosclerosis, hypercholesterolemia, diabetes mellitus or obesity. Peroxynitrite scavenging activities and HPLC analysis on the five Oriental medicinal drugs belonging to the genus Citrus, Aurantium or Poncirus (Rutaceae family) and HPLC analysis were taken to evaluate flavanone glycosides with peroxynitrite scavenging activity. The $IC_{50}s$ of the five crude drugs were shown as follows: Aurantii nobilis Pericarpium (Jinpi, 18.3 ${\mu}g$/ml), Citrii unshiu Pericarpium (Chungpi, 7.50${\mu}g$/ml), Citrii unshiu Semen (Gyulhaek, >50.0${\mu}g$/ml), Aurantii Fructus (Jigak, 18.3${\mu}g$/ml), and Poncirii Fructus (Jisil, >50.0${\mu}g$/ml) where Korean crude drug's names are noted in the parenthesis. Peroxynitrite scavenging effect of flavanones or their glycosides usually contained in Citrus species were observed as follows: hesperetin (1.89 ${\mu}g$/ml), naringenin (7.77 ${\mu}g$/ml), hesperidin (8.44 ${\mu}g$/ml), poncirin (>50.0 ${\mu}g$/ml)and ponciretin(>50.0 ${\mu}g$/ml). The activities of naringin and poncirin with ${\alpha}$-L-rhamnopyranosyl($1{\rightarrow}2$)-${\beta}$-D-glucopyranosyl moiety were weak. HPLC analytical data revealed that Jinpi (the peels of mature fruits of Citrus unshiu) and Chungpi (the peels of immature fruits of C. unshiu) had high quantities of hesperidin as the value of 142.1${\pm}$0.21 and 104.51${\pm}$1.10 mg/g dried weight, respectively. Poncirin was clearly detected in only Jisil and naringenin and naringin were not observed on the HPLC chromatogram of the five crude drugs.

• Research in Community and Public Health Nursing
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• v.5 no.2
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• pp.181-202
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• 1994

This study was conducted in order to grasp the condition of the student's knowledge and attitude about tuberculosis. And to offer the basic materials for the prevent tuberculosis in elementary school. The objects were comprised 395 of volunteered 6th grade students who study in two elementary schools. The material of this study was the questionaire(chronbach $\alpha=.9016$) suited to the purposed of this research which has been made through studying references. All the questionaire were collected immediately without explanation. The data was collected from 13rd to 25th of May on 1994. Analysis of the data was done utilizing SPSS for percentage, mean, ANOVA and pearson-Correlation Coefficient. The Result are as follows; 1. General features of the objects of study. Sex distribution was similar. Salary of 1000-1500 thousand won were highest (40.2%), nuclear family was highest (87.1%), fathers of graduated high school were the highest(44.0%), mothers of graduated high school were the highest(56.8%). And there was nobody about tuberculosis patient in one's close relatives were highest(95.4%). 2. The conditions of attitude about tuberculosis. Having experience of tuberculin test were highest(59.0%). Less than 9mm indulation among the tuberculin tested group were 85.1%, more than indulation were 14.9%. Have a B. C. G. injection among the less than 9mm indulation were 83.2%. Leave alone among the more than 10mm indulation were 56.0%. Think it too much trouble to do not tuberculine test were 63.0%. Do not take a chest X-ray in the past were 60.3%. And take a chest X-ray in the past were 39.7%. Health educated group was 74.3%. If tuberculosis sign was developed, notified to parent was 73.8%. 3. The condition of knowledge about tuberculosis. When 5 points was given to 'very affiming' and 1 point was given to 'very deny', the total average was 3.54. And symptom of tuberculosis secion was 3.67, vaccination of tuberculosis section was 3.66, tuberculine test section was 3.56, epidemiology of tuberculosis section was 3.54, infection of tuberculosis section was 3.38. And every section showed affirmative correlation(P<.001). 4. Correlation between the general features and attitude variables. High incomed group may have more attitude on tuberculin test than low incomed group($x^2=16.$ 190, P<.01). High educated group may have more attitude on tuberculin test than low educated group(Father : $x^2=28.530$, P<.001, Mother: $x^2=26.060$, P<.001). High educated group may have more attitude on health education than low educated group(Father: $x^2=20.$ 767, P<.000, Mother: $x^2=10.639$, P<.05). Nuclear family may have more attitude on notify to parent than others($x^2=51.45$, P<.000). Tuberculosis patient in one's close associates have more attitude on notify to parent than others($x^2=51.$ 45, P<.000). 5. Difference between the general features and knowledge of tuberculosis. High incomed group were highest score in knowledge (F=3.99, P<.01). High educated group were highest score in knowledge(Father : F=8.81, P<.000, Mother: F=9.09, P<.000). 6. Difference between the attitude and knowledge of tuberculosis. Tuberculin tested group were highest score in knowledge(t=9.88, P<.000). Taken chest X-ray group were highest score in knowledge (t=2.07, P<.05). Received health education group were highest score in knowledge(t=6.83, P<.000). Notified symptoms to teachers and parent group were highest score in knowledge(F=3.89, P<.01).

• Journal of Aquaculture
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• v.13 no.4
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• pp.339-351
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• 2000

Optimal environmental conditions, that sustained fastest growth, lowest mortality and abnormality of the scallop Patinopecten yessoensis, were identified from field experiments undertaken at Chumunjin during 1991-1998. Temperature within the water column 10~30 m depth ranged between 5 and 23$^{\circ}C$; high temperature and daily fluctuation resulted in growth retardation and heavy mortality of the scallop. Optimal salinity range was between 31.5 and 34.5%0 and water transparency 6.0 and 18.1 m, which was significantly affected by phytoplankton density. Chlorophyll concentration ranged between 0.04 and 3.51 f.lgfL. Low temperature and high chlorophyll concentration appear to support faster growth of the scallop. Optimal periods of transplantation for intermediate culture were between mid July and early November: cultured under high density during July-August as a first step and under low density during mid September through early November as a second step. Optimal stocking density in square net cage (<35${\times}$35 em) for intermediate culture was 30-40 individuals per cage for main culture using lantern net and 80 -100 individuals of the size of 1.5 ~ 3.0 em shell height per cage for sowing culture. During the intermediate culture, the highest growth was realized, when the cage was held at water depth between 10 and 15 m. Water depth below 25 m, however, was best to avoid mass mortality during the periods of abnormally high water temperature and high variation of water temperature. The daily growth rate during the intermediate culture was between 0.019~0.381 mm; low in January and February but high in March and April. It is suggested that the main culture is commenced before June under low stocking density to avoid the possibility of mass mortality during summer by high water temperature.