• Applied Biological Chemistry
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• v.41 no.1
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• pp.6-12
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• 1998

To extract insoluble proteins and to improve functional properties of abolished proteins, a protease producing Aspergillus sp. MS-18 was isolated from soil. The enzyme was purified and its enzymological characteristics were investigated. It was found that production of protease reached to the maximum when the wheat brae medium containing, 3% arabinose, 0.5% polypepton, 0.1% $(NH_4)_2SO_4$ and 0.2% magnesium chloride was cultured for 3 days. Protease was purified 16.9 folds after ion exchange chromatography and gel filtration and the specific activity was 340.4 unit/mg. Purified enzyme was confirmed as a single band by the polyacrylamide gel electrophoresis. The molecular weight of protease was estimated to be 30,000. Crystalization form of purified protease was a stick shape with rounding edges. The optimum pH and temperature for the protease activity were 9.0 and $60^{\circ}C$, respectively. The enzyme was stable in pH 7.0-12.0 at $50^{\circ}C$. The activity of purified enzyme was inhibited by $Hg^{2+}$, $Cu^{2+}$, $Zn^{2+}$ and $Pb^{2+}$, whereas it was activited by $Na^+$, $Mg^{2+}$ and $Mn^{2+}$. The activity of the protease was inhibited by the treatment with ethylenediaminetetraacetic acid and phenylmethane sulfonyl fluoride. The result suggests that the purified enzyme is a serine protease with metal ion at active site. Km and Vmax of purified protease were $29.33\;{\mu}mole/L$ and $5.13\;{\mu}g/min$, respectively.

• Journal of Pharmaceutical Investigation
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• v.39 no.6
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• pp.393-400
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• 2009

PHEA (hydroxyethyl-aspartamide)-mPEG (methoy-polyethyleneglycol)-$C_{16}$ (hexadecylamine)-ED (ethylenediamine) was prepared as a drug delivery carrier. The structure and molecular weight of polymers were characterized by $^1H$-NMR and gel permeation chromatography. Micelle size and shape were measured by electro-photometer light scattering and transmission electron microscope. The mean diameter of micelles was 23 nm in aqueous solution. To evaluate the potential of these polymeric micelles as a drug carrier, PSI-mPEG-$C_{16}$-ED was conjugated with Cy5.5 for Near-Infrared Fluorescent (NIRF) based optical imaging. PSI-mPEG-$C_{16}$-ED-Cy5.5 was injected intravenously into mice (n=5) and in vivo NIRF imaging was performed during 48 h after injection. The biodistribution study at 24 h after injection showed the longcirculation property of PSI-mPEG-$C_{16}$-ED-Cy5.5. Therefore, PSI-mPEG-$C_{16}$-ED micelles could be a promising drug carrier and imaging agent.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3990-3996
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• 2014

Because the physical properties can be decreased when a Nylon 66/glass fiber composite is injected into a mold over $300^{\circ}C$, a systematic study of the thermal history in the case of re-use is needed. Nylon 66/glass fiber extrudates as a function of the extrusion number were prepared using a twin screw extruder at 305/290/273/268/265/$260^{\circ}C$. The chemical structure, thermal properties, melt index, crystal structure, Izod impact strength, and rheological properties were measured by Fourier transform infra-red (FT-IR), melt indexer, DSC, TGA, XRD, Izod impact tester, and dynamic rheometer. The FT-IR spectra indicated that the number of extrusions did not affect the chemical structure. The decrease in molecular weight with increasing extrusion number was confirmed by the melt index and the complex viscosity of extrudates. Based on the DSC and TGA results, the thermal history had no effect on the melting temperature, regardless of the number of extrusions, but the degradation temperature decreased up to $20^{\circ}C$ with increasing extrusion number. The Izod impact strengths of the extrudates were found to decrease with increasing extrusion number. No structural change after extrusion was also confirmed because there was no change in the slope and shape of the G'-G" plot.

• The Korean Journal of Pesticide Science
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• v.15 no.2
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• pp.166-176
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• 2011

Bacillus thuringiensis CAB530 was isolated from dead Anomata albopilosa (Rutelidae: Coleoptera) and soil of green tea field, and confirmed its insecticidal activities. CAB530 isolate showed a high insecticidal activity against the beet armyworm among the many lepidopteran insects that are difficult to control. $LC_{50}$ value of CAB530 isolate against the second larva of Spodoptera exigua was $1.49{times}10^4$ spore concentration (cfu/$m{\ell}$). SDS-PAGE result of insecticidal toxin protein of CAB530 isolate showed a band at 130 kDa that is similar pattern with B. thuringiensis subsp. kurstaki that took insecticidal activity against S. exigua. Otherwise, the crystal protein of the CAB530 isolate was conformed at 65 kDa level after 30 minute of incubation in S. exigua midgut juice. Six crystal genes (cry1Aa, cry1Ab, cry1C, cry1D, cry1F and cry1I) were identified by PCR. It different from genes of B. thuringiensis subsp. kurstaki. Crystal shape and pattern of toxin protein was similar with B. thuringiensis subsp. kurstaki, however, insecticidal activity and PCR result of CAB530 isolate was similar with B. thuringiensis subsp. aizawai.

• Korean Journal of Plant Taxonomy
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• v.42 no.4
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• pp.260-266
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• 2012

Because the embryological features of Jeffersonia dubia are poorly understood, we conducted the first embryological study comparing it to other related genera of Berberidaceae. Important embryological features of J. dubia are as follows: the anther is tetrasporangiate, anther wall formation confirms basic type, glandular tapetum cells are two nucleate, the epidermis persistent, and the endothecium develops fibrous thickenings, anther dehiscence by two valves, meiosis in a microspore mother cell is accompanied by simultaneous cytokinesis, microspore tetrads are usually tetrahedral, pollen grains two cells at the time of anthesis. The ovule is bitegmic, anatropous and crassinucellate, archesporium single celled, development of the embryo sac Polygonum type, a mature embryo sac is ellipsoidal in shape. Endosperm formation is of Nuclear type and embryogeny Onagrad type. Seeds are arillate and seed coat exotestal type. Embryological comparisons showed that Jeffersonia resemble to Epimedium and Vancouveria rather than Berberis and Mahonia in some features, like as number of tapetal cells, cytokinesis in meiosis, and thickness of exotesta. It also resembles to Gymnospermium in mode of anther wall formation, number of tapetal cells, formation of nucellar cap, and nature of antipodal cells. Nevertheless, Jeffersonia and Gymnospermium differ from several other embryological features and molecular data too. Therefore, embryological evidences support that Jeffersonia is closely related with Epimedium and Vancouveria.

• Journal of the Korean Society of Tobacco Science
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• v.2 no.1
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• pp.1-7
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• 1980

Gel filtration column chromatography (Sephadex G-75), dialysis an d Brushite column chromatography were carried out to separate the brown pigmented macromolecule from water extracts of the cured leaf tobaccos. The two distinct macromolecules having different molecular weight were separated by the Sephadex column chromatography. Brushite also separated two different species of macromolecules which might have different electronic structures. According to the enzymatic degradation of protein in Burley and Hicks, chymotrypsin showed the best degradation ratio, ie., 16-30% in Burley and 38-57% in Hicks. Similar effect was observed with pepsin. However, very low effect of degradation was revealed with trypsin. The sample treated with the proteolytic enzymes revealed the disappearance of the first peak and the slight decrease of the 2nd peak height in the separation profile of Sephadex. After dialysis, the brown pigmented macromolecule was pyrolyzed at $300^{\circ}C$ and the strongly fluorescent components not identified before pyrolysis were detected with TLC separation. Absorption spectrum of these fluorescent compounds was monitored in benzene and the absorption maxima at 265nm and 275 nm were obtained. Considering absorption maxima and shape of the spectrum, those fluorescent compounds seem to be PAH derivatives.

• Molecules and Cells
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• v.43 no.4
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• pp.360-372
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• 2020

The basal ganglia network has been implicated in the control of adaptive behavior, possibly by integrating motor learning and motivational processes. Both positive and negative reinforcement appear to shape our behavioral adaptation by modulating the function of the basal ganglia. Here, we examined a transgenic mouse line (G2CT) in which synaptic transmissions onto the medium spiny neurons (MSNs) of the basal ganglia are depressed. We found that the level of collaterals from direct pathway MSNs in the external segment of the globus pallidus (GPe) ('bridging collaterals') was decreased in these mice, and this was accompanied by behavioral inhibition under stress. Furthermore, additional manipulations that could further decrease or restore the level of the bridging collaterals resulted in an increase in behavioral inhibition or active behavior in the G2CT mice, respectively. Collectively, our data indicate that the striatum of the basal ganglia network integrates negative emotions and controls appropriate coping responses in which the bridging collateral connections in the GPe play a critical regulatory role.

• Research in Plant Disease
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• v.12 no.3
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• pp.226-230
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• 2006

Cucumber mosaic virus(CMV) was occurred on red pepper showing vein chlorosis or vein necrosis with the incidence rate of 52% from 62 specimens collected in natural fields. Among 32 samples infected with CMV, the specimens of 22 red pepper leaves showing vein chlorosis were infected singly with CMV-VCH. CMV-VCH induced vein chlorosis on the inoculated leaves, and vein banding and vein necrosis on the upper leaves of Nicotiana glutinosa, and then killed after showing bud necrosis. The typical symptoms of vein banding, malformation and blister were produced on the upper leaves of Nicotiana benthamiana and N. tabacum 'Ky-57' without symptoms on the inoculated leaves. The commercial cultivars of 'Bugang', 'Manitta' and 'Gwariput' were shown the typical symptom of vein chlorosis by the mechanical inoculation of CMV-VCH. CMV-VCH was detected specifically by RT-PCR. Virus particles of CMV-VCH were isometric shape having 30 nm diameter. Ultraviolet absorption of purified CMV-VCH was maximum at 260 nm and minimum at 242 nm. The ratio of A260/A280 was 1.71. CMV-VCH had the single nucleo-protein having the molecular weight of 24.5 kDa.

• Journal of the Korean Society for Precision Engineering
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• v.3 no.1
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• pp.40-49
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• 1986

Crack, craze and void are common defects which may be found in the bulk of polymeric materials such as either themoplastics or thermosets. The healing phenomena, autohesion, of these defects are known to be a intrinsic material property of various polymeric materials. However, only a few experimental and theoretical investigations on crack, void and craze healing phenomena for various polymeric materials have been reported up to date [1, 2, 3]. This may be partly due to the complications of healing processes and lacking of appropriate theoretical developments. Recently, some investigators have been urged to study the healing phenomena of various polymenic materials since the significance of the use of polymer based alloys or composites has been raised in terms of specific strength and energy saving. In the earlier published reports [1, 2, 3, 4], the crack and void healing velocity, healing toughness and some other healing mechanical and physical properties were measured experimentally and compared with predicted values by utilizing a simple model such as the reptation model under some resonable assumptions. It seems, however, that the general acceptance of the proposed modeling analyses is yet open question. The crack healing processes seem to be complicate and highly dependent on the state of virgin material in terms of mechanical and physical properties. Furthermore, it is also strongly dependent on the histories of crack, craze and void development including fracture suface morphology, the shape of void and the degree of disentanglement of fibril in the craze. The rate of crack healing may be a function of environmental factors such as healing temperature, time and pressure which gives different contact configurations between two separated surfaces. It seems to be reasonable to assume that the crack healing processes may be divided in several distinguished steps like stress relaxation with molecular chain arrangement, surface contact (wetting), inter- diffusion process and com;oete healing (to obtain the original strength). In this context, it is likely that we no longer have to accept the limitation of cumulative damage theories and fatigue life if it is probable to remove the defects such as crack, craze and void and to restore the original strength of polymers or polymer based compowites by suitable choice of healing histories and methods. In this paper, we wish to present a very simple and intuitive theoretical model for the prediction of healed fracture toughness of cracked or defective polymeric components. The central idea of this investigation, thus, may be the modeling of behavior of chain molecules under healing conditions including the effects of chain scission on the healing processes. The validity of this proposed model will be studied by making comparisons between theoretically predicted values and experimentally determined results in near future and will be reported elsewhere.

• Journal of fish pathology
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• v.11 no.2
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• pp.129-136
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• 1998

In March 1997, a new rhabdovirus was isolated from moribund cultured Japanese flounder Paralichthys olivaceus in sea water tank and cage culture systems in Kyung-Nam and Chun-Nam province, Korea. At temperature $15^{\circ}C$ the virus replicated and induced cytopathic effects (CPE), which progressed to eventual cytolysis, in susceptible cell lines, including RTG-2 and EPC. The CHES-214 cell line was refractory. Virus particles were bullet-shaped and measured $70nm{\times}100$ to 150 nm in size. The isolate was sensitive to pH 3, to diethyl ether, and to heat ($50^{\circ}C$ 5 min, $60^{\circ}C$ 1 min). Viral replication was not inhibited by $10^{-4}$ M 5-iododeoxyuridine. Virus infectivity was reduced by anti-HRV (8401-H) rabbit serum, but can not reduced by antisera against infectious hematopoietic necrosis virus (IHNV), chum salmon reovirus (CSV), retrovirus of salmonid (RVS) and infectious pancreatic necrosis virus (IPNV). HRV virus antigen was detected by fluorescent antibody test (FAT) in the cytoplasm of infected EPC cell. Purified isolates virions were composed of: polymerase (L), glycoprotein (G), nucleoprotein (N) and 2 matrix proteins (M1 and M2). Based upon their relative mobilities, the estimated molecular weights of the proteins were: L, 160 kDa; G, 55 kDa; N, 45 kDa; M1, 26 kDa; and M2, 22 kDa.