• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.8
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• pp.919-928
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• 2017

The immuno-enhancing effects of alginate oligosaccharides from Sargassum coreanum were investigated. The alginate oligosaccharides were produced by an alginate-degrading enzyme from S. oneidensis PKA 1008. The degraded alginate oligosaccharides were visualized by thin-layer chromatography developed using a solvent system of 1-butanol/methanol/water, 4:1:2 (v/v/v). Alginate was degraded into dimmers at 60 h. As a result, the levels of Th1 cytokine [interferon $(IFN)-{\gamma}$ and interleukin (IL)-2] and Th2 cytokine (IL-6 and IL-10) increased with increasing incubation time compared to the control in vitro. Enzymatic extract treatment promoted proliferation of splenocytes at concentrations of 100 and 200 mg/kg at 24 h in vivo. Secretion of $IFN-{\gamma}$ and IL-2 significantly increased in a dose-dependent manner at 24 h as well as induced higher production of IgG2a in serum. Natural killer cell activity was measured and tended to increase. In addition, complete blood cell counts increased in a dose-dependent manner. These results indicate that alginate oligosaccharides produced by crude enzyme from S. oneidensis PKA 1008 may have significant immune activities.

• Journal of Life Science
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• v.28 no.9
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• pp.1056-1061
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• 2018

This article reports an agar-degrading marine bacterium and characterizes its agarase. The agar-degrading marine bacterium, KC-1, was isolated from seawater on the shores of Sacheon, in Gyeongnam province, Korea, using Marine Broth 2216 agar medium. To identify the agar-degrading bacterium as Agarivorans sp. KC-1, phylogenetic analysis based on the 16S rRNA gene sequence was used. An extracellular agarase was prepared from a culture medium of Agarivorans sp. KC-1, and used for the characterization of enzyme. The relative activities at 20, 30, 40, 50, 60, and $70^{\circ}C$ were 65, 91, 96, 100, 77, and 35%, respectively. The relative activities at pH 5, 6, 7, and 8 were 93, 100, 87, and 82%, respectively. The extracellular agarase showed maximum activity (254 units/l) at pH 6.0 and $50^{\circ}C$ in 20 mM of Tris-HCl buffer. The agarase activity was maintained at 90% or more until 2 hr exposure at $20^{\circ}C$, $30^{\circ}C$ and $40^{\circ}C$, but it was found that the activity decreased sharply from $60^{\circ}C$. A zymogram analysis showed that Agarivorans sp. KC-1 produced 3 agar-degrading enzymes that had molecular weights of 130, 80, and 69 kDa. A thin layer chromatography analysis suggested that Agarivorans sp. KC-1 produced extracellular ${\beta}$-agarases as it hydrolyzed agarose to produce neoagarooligosaccharides, including neoagarohexaose (21.6%), neoagarotetraose (32.2%), and neoagarobiose (46.2%). These results suggest that Agarivorans sp. KC-1 and its thermotolerant ${\beta}$-agarase would be useful for the production of neoagarooligosaccharides that inhibit bacterial growth and delay starch degradation.

• Journal of radiological science and technology
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• v.37 no.4
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• pp.341-348
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• 2014

Wedge filter could use to increase the dose distribution at the hot dose regions. We evaluated dose discrepancy at surface and build region in the infield and outfield that Metal Wedge (MW) and Enhance Dynamic Wedge (EDW) were interact with photon. In this paper, we used Gafchromic EBT3 film that had excellent spatial resolution, composed the water equivalent materials and changed the optical density without development. The set up conditions of linear accelerator were fixed 6 MV photon, 100 cm SSD, $10{\times}10cm^2$ field size and were irradiated 400 cGy at Dmax. The dose distribution and absorbed dose were evaluated when we compared the open field with $15^{\circ}$, $30^{\circ}$, $45^{\circ}$ metal wedge and enhanced dynamic wedge. A $15^{\circ}$ metal wedge could increase the surface and build up region dose than using a $15^{\circ}$ enhanced dynamic wedge. A $30^{\circ}$ metal wedge could decrease the surface and build up region dose than using a $30^{\circ}$ enhanced dynamic wedge. A $45^{\circ}$ metal wedge could decrease by large deviation the surface and build up region dose than using a $15^{\circ}$ enhanced dynamic wedge. The dose of penumbra region at outfield were increased on the thick side but were decreased on the thin side. It could be decrease the surface dose and build up region dose, if the metal wedge filters were properly used to make a good dose distribution and not closed the distance of surface.

• KDI Journal of Economic Policy
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• v.12 no.3
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• pp.153-172
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• 1990

The present paper investigates the potential value of strategic antitrust policy in an oligopolistic international market. The market is characterized by a non-cooperative Cournot-Nash equilibrium and by asymmetry in costs among firms in the world market. The model is useful for two reasons. First, it is important in the context of policy-making to examine the conditions under which it may be beneficial to relax antitrust law to enhance competitiveness. Second, the explicit derivation of the level of cost-saving required for a gain in total domestic surplus provides an empirical rule for excluding industries that do not satisfy the requirements for a socially beneficial antitrust exemption. Results of the analysis include a criterion that tells how the cost-saving and concentration effects of a merger offset each other. The criterion is derived from fairly general assumptions on demand functions and is simple enough to be applied as a part of the merger guidelines. Another interesting policy implication of our analysis is that promoting mergers would not be a beneficial strategy in a net importing industry where cost-saving opportunities are thin. Cost-saving domestic mergers are more likely to increase national welfare in exporting industries. The best candidate industries for application of strategic antitrust policy are those with the following characteristics: (i) a large potential for efficiency enhancement; (ii) high market concentration at the world but not the domestic level; (iii) a high ratio of exports to imports. Recently, many policymakers and economists in Korea have also come to believe that the appropriate antitrust policy in an era of increased foreign competition may actually be to encourage rather than to prohibit domestic mergers. The Industry Development Act of 1986 and the proposed bill for Mergers and Conversions in the Financial Industry of 1990 reflect this changing perspective on antitrust policy. Antitrust laws may burden domestic firms in the sense that they have a more constrained strategy set. Expenditures to avoid antitrust attacks could also increase costs for domestic firms. But there is no clear evidence that the impact of antitrust policy is significant enough to harm the competitiveness of domestic firms. As a matter of fact, it is necessary for domestic financial institutions to become large in scale in this era of globalization. However, the absence of empirical evidence for efficiency enhancement from mergers suggests caution in the relaxation of antitrust standards.

• Applied Microscopy
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• v.30 no.4
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• pp.357-365
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• 2000

Paneth cells have been suggested to contribute to the elimination of excess metals into the intestinal lumen. The purpose of this study wat to investigate the changes of the zinc pools in rats subjected to functional loading with zinc salt by mean of both light and electron microscopical autometallography (AMG). Wistar rats 4 were administrated with zinc chloride (20 mg/kg body weight) intraperitoneally dissolved in 1 ml distilled water. The control group received 1 ml saline IP. After further one hour the animals were transcardially perfused with 0.4% sodium sulphide dissolved in 0.1 M PB fellowed by 3% glutaraldehyde solution for 10 minutes. Pieces of ileum were frozen with solid $CO_2$ and sectioned on a cryostat. The sections $(20{\mu}m)$ were autometallographically developed. Sections selected for EM were reembedded on top of a blank Epon block, from which ultrathin sections (100 nm) were cut. The ultrathin sections were double stained with uranyl acetate (30 min) and lead citrate (5 min), then examined under electron microscope. Studies of comparable sections from control and zinc loaded animals with the AMG selenium method gave quite different results. The control animals demonstrated a weakly positive staining in the cytoplasm of the Paneth cells. In the electron microscope the AMG silver grains were found to be located in the cytoplasm, while the electron dense secretary granules and other cell organelles were void of staining. Few AMG grains were located at the apical surface of the Paneth cells. In sections from zinc loaded rats, the AMG grains were seen in abundance in the lumen of the Lieberkuhn crypts at light microscopic levels. At EM levels the zinc revealing silver grains were located in the cytoplasm as in the controls, but much more AMG grains were shifted into the secretary granules. Furthermore, profound AMG grains were found in the lumen of the crypts and surrounding vessels. And a few grains were seen in the endothelium. The AMG technique demonstrated a pattern of AMG grains in the Paneth cells that strongly suggests a transport of zinc ions through these cells.

• Journal of Korea Soil Environment Society
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• v.5 no.2
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• pp.55-66
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• 2000

A U.S EPA Synthetic soil matrix was used for reference neat soil and pyrene contaminated soil. For the contaminated soil, 4.79 wt.% pyrene was dissolved completely into the djchlorornethane, and the soil was evenly soaked with the pyrene solution. The contaminated soil samples(50$\pm$0.5mg) were heated in a modified electrical screen heater reactor which consisted of a thin stainless foil (3.5cm$\times$13cm$\times$0.00254cm, 302 stainless steel shim), two electrodes, and a 20cm dia. $\times$30cm tall cylindrical Pyrex chamber sealed at both ends by aluminum flanges. The heating rate and time conditions were selected as $455^{\circ}C$ @ $1137^{\circ}C$ /s, $760^{\circ}C$ @ $950^{\circ}C$ /s and $977^{\circ}C$ @ $977^{\circ}C$/s. Tar samples after heating the soils were collected on the aluminum foil funnel and a glass filter paper (25mm dia. filter paper) The tar sample and remnant soil on the reactor were extracted with dichloromethane covering the filters, foils and soil by sonicating each in the waterbath for 10 minutes. The extractions were run on a HPLC. At the low peak temperature(about $455^{\circ}C$ @ $1137^{\circ}C$/s) the color of tar was "white", at the middle peak temperature (about 76$0^{\circ}C$ @ 95$0^{\circ}C$/s) the color of tar was "pink brown", at the high peak temperature (about 977$^{\circ}C$ @ 977$^{\circ}C$/s) the color of tar was "dark brown". Cyclopeta(cd)pyrene (CPEP) , which is an interesting species due to mutagenic effect on human cells, was detected in tar samples only above the middle peak temperature. This species was not detected at the low peak temperature. Six isomers of bipyrene were detected. Phenanthrene(C$_{14}$ $H_{10}$) and cyclopenta(def)phenanthrene(C$_{15}$ $H_{10}$) were also detected, but their content was very small relative to the other listed compounds.to the other listed compounds.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.11
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• pp.1-9
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• 1972

For a measure against late transplanting, this experiment was conducted to investigate a reasonable seeding rate in nursery bed and a proper nursery size. The treatments applied to this experiment are as follows a) seeding rates: 0.2ι, 0.4ι and 0.6ι per 3.3$m^2$ b) nursery sizes. for 10a-field area: 39.6$m^2$, 49.5$m^2$ and 59.4$m^2$ c) transplanting dates: June 5, June 25 and July 15. The seeding date was April 26 and planting density was determined by the number of sound seedlings based on the combination of seeding rate and nursery size. The results may be summarized as follows: 1. In seedlings both increased nursery period and decreased seeding rate showed a remarkable-increase in plant height, number of leaves, dry matter weight and the ratio of dry weight to plant height. But their number of tillers and live leaves did not show such tendency. 2. Delayed transplanting date shortened culm length and panicle length as well as number of days from transplating to heading and it also delayed heading date. On the other hand the transplanting of 80-day seedlings resulted in premature heading. 3. As a result late transplanting reduced number of spikelets per panicle, maturing rate and 1000-grain weight. In the last analysis it linearly reduced grain yield. The decreasing rate of yield by late transplanting was 15.6% in June 25 plot and 41. 3% in July 15 plot, compared with the yield in June 5 plot. Such a remarkable decrease in yield of the extremely late transplanted plot was mainly due to markedly decreasing number of spikelets per panicle and 1000-grain weight. 4. Both increased seeding rate and nursery size gave a rise in number of tillers per unit area as well as number of transplanting hills but gave a fall in culm length and panicle length. 5. Accordingly, though thick seeded - dense planted plot increased number of panicles per unit area, decrease in number of spikelets per panicle and 1000-grain weight made no differences in yield between thick seeded - dense planted plot and thin seeded - sparse planted one. However, the yield in the thick seeded - dense planted plot transplanted on July 15 was reduced owing to the remarkable decrease in maturing rate and 1000-grain weight. 6. We came to the conclusion that as a measure against the extremely late transplanting the suitable seeding rate was 0.4ι per 3.3$m^2$ and the proper nursery size was 59.4$m^2$ for 10a-field area.

• Journal of Life Science
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• v.18 no.2
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• pp.167-174
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• 2008

Antimicrobial activity of Zanthoxylum piperitum was investigated against Streptococcus mutans that causes dental caries. Although the methylene chloride extract of seeds exhibited higher antimicrobial activity than other organic solvent extracts, including methanol, ethyl acetate, and hexane extracts of pericarps or seeds of Z. piperitum, essential oils prepared from both seeds and pericarps possessed more potent inhibitory activity than the methylene chloride extract of seeds. The minimal inhibitory concentrations (MICs) of the essential oils of seeds and pericarps were 0.3 mg/ml and 4.0 mg/ml against S. mutans, respectively. When the seed essential oil was further separated into seven fractions (CS-SD-A${\sim}$CS-SD-G) by thin layer chromatography (TLC), all fractions exhibited lower antimicrobial activity than the essential oil. To understand the antimicrobial ingredients of Z. piperitum, seeds the gas chromatography-mass spectrometry (GC-MS) data of the methylene chloride extract of seeds was compared with those of the seed essential oil (CS-SD). Whereas the methylene chloride extract of seeds contained carvacrol (0.24%), ${\beta}$-caryophyllene (1.72%), and ${\alpha}$-humulene (0.88%), which were previously known to inhibit growth of S. mutans, the seed essential oil contained sabinene (1.57%), linalool (1.55%), citronellal (13.67%), terpinene-4-ol (0.45%), citronellol (3.69%), geraniol (0.9%), linalyl acetate (1.35%), ${\beta}$-caryophyllene (1.35%), ${\alpha}$-humulene (0.78%), and ${\delta}$-cadinene (0.67%) in this regard. These results indicate that Z. piperitum seeds possess various inhibitory substances against S. mutans, and an effective method to isolate the active ingredients from the seeds is to prepare the essential oil. These results also suggest that the essential oil of Z. piperitium seeds may be applicable to preventing dental caries.

• Journal of the Korean Society of Costume
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• v.39
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• pp.113-123
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• 1998

This study focuses on the effects of the clothes worn by kisaeng; courtesans trained in singing and dancing, on changes in female psychology as reflected in general women's fashions during the later years of the Chosun dynasty. During this period, the social order had broken down considerable, due in part to the introduction of Roman Catholicism, and in part to the actions of Sil-hak, who emphasized open-ness and practicality in the organization of social affairs. This freer social environment disrup-ted the established social hierarchies. The kisaeng were among the first to respond to the new social mores by adopting more colorful, sensual, and individualized fashions. Their social position allowed them to reflect the new aesthetics of the time right away. Those aesthetics seemed to lay great emphasis on the artistic effects of contrast. The kisaeng would adorn their heads with large Kache (an elaborate wig or hairdo typically reserved for use by women in full formal dress). In contrast to this conspicuous hairstyle, they typically wore very tight-fitting Jogori (short-cropped Korean traditional jackets for women) around their upper torsos. The long skirts emerging from beneath these short jackets would typically flare out dramatically, with the aid of petticoats. However, these skirts would be bound at the waist with a sash, increasing the sexual suggestiveness of the clothing by drawing at-tention to the hips, and by exposing the bottom frills of the petticoats, or the wide pantal-oons and other undergarments the kisaeng wore to add volume to their skirts. The relative freedom enjoyed by the kisaeng to experiment with new fashions was not widely shared by most women. This generated envy from women of the noble classes, who were more bound by convention, and restrained from adopting such a mode of dress. It also generated envy from women of the humble classes, who saw the kisaeng as working little for their wealth, and yet dressing every day in finery that the average women would only ever be able to afford on her wedding day. This envy directed at the relative freedom/wealth of the kisaeng by women who faced greater socioeconomic constraints was given cultural expression through the adoption of elements of the kisaeng's fashion in the fashions of both noblewomen and humble women in old korea. The luxurious Kache sported by the kisaeng had in fact been borrowed from the habitual attire of upper-class women. So to distinguish themeselves from the kisaeng, they began to abandon these elaborate hairstyles in favor of traditional ceremonial hoods (Nel-ul-a thin black women's hood) and coronets (Suegaechima). This supposed reaction to the abuse of the Kache by the kisaeng still remained influenced by the kisaeng still remained influence by the kisaeng, however, as these headdresses became adorned with many more jewels and decorations, in imitation of the kisaeng's adaptations of the coronet. At the same time, noblewomen began sporting the Jangwue ; a headdress previously worn only by kisaeng and lower class women, and lower class women were then permitted to wear the Kache at weddings. All women behan to wear shorter, tighter Jogori jackets, and to add volume to their skirts. They also attached frills to their under-garments in imitation of the kisaeng's exposed petticoats and pantaloons. The impact of kisaeng fashions was thus deep and widespread, and can be understood as an expression of women's longing for freedom from socioeconomic constraints in the late Chosun dynasty. This study adopts an interdisciplinary ap-proach to the understanding of historical changes in women's fashions. Such interdisciplinary work can greatly enrich the study of fashion, often narrowly focused on clothing morphology and broad generalizations about society. For this reason, specific dynamics of feminine psychology in the late Chosun dynasty were elaborated in this study, to provide a deeper under-standing of the changes in fashion underpinned by them. If more such detailed analyses are undertaken, a whole new understanding of changes in fashion can be generated, and perhaps a transformation of the field of fashion history can be ultimately achieved.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.2
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• pp.88-94
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• 2020

Purpose: The purpose of this study was to analyze the sagittal root position of maxillary anterior teeth and report the frequency of each classification in Korean for immediate implant placement. Materials and Methods: A retrospective review of cone-beam computed tomography (cone-beam CT) images was conducted on 120 patients (60 male and 60 female) who fulfilled the inclusion criteria. After reorientation of the axis, cone-beam CT images were evaluated and the relationship of the sagittal root position (SRP) of the maxillary anterior teeth to its associated osseous housing was recorded. Class I, II, and III were classified respectively when the root was positioned on the labial, central, and palatal aspect of the alveolar bone. Class IV was the position that at least two thirds of the root is engaging both the labial and palatal cortical plates. Then, the angulation of the root axis and the alveolar bone axis was measured. Descriptive statistics and Kruskal-Wallis test were used to compare the angulation according to the root position and SRP class. Results: The frequency distribution of sagittal root position of maxillary anterior teeth indicated that 81.1%, 10.3%, 1.9%, and 6.7% were classified as Class I, II, III, and IV, respectively. The sagittal angulation at approximately 77.5% of central incisor, lateral incisor, and canine was < 20 degrees, but the angle at more than 42.7% of canine was ≥ 20 degrees. Within the class, the angulation was statistically significantly greater in Class I (16.19) compared to Class II (8.72) and Class III (9.93), and smaller in Class IV (3.79). Conclusion: Within the limitation of this study, a majority of the maxillary anterior roots were positioned close to the buccal cortical plate. However, some roots have very thin alveolar bone and sagittal angulation larger than 30 degrees. Therefore, cone-beam CT analyses of the sagittal root position and the sagittal angulation are recommended for the selection of the appropriate dental implant treatment approach.