• The Korean Journal of Physiology and Pharmacology
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• v.13 no.1
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• pp.39-47
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• 2009

Gaegurin 4(GGN 4), an antimicrobial peptide isolated from a Korean frog, is five times more potent against Gram-positive than Gram-negative bacteria, but has little hemolytic activity. To understand the mechanism of such cell selectivity, we examined GGN4-induced $K^+$ efflux from target cells, and membrane conductances in planar lipid bilayers. The $K^+$ efflux from Gram-positive M. luteus(2.5 ${\mu}g/ml$) was faster and larger than that from Gram-negative E. coli(75 ${\mu}g/ml$), while that from RBC was negligible even at higher concentration(100 ${\mu}g/ml$). GGN4 induced larger conductances in the planar bilayers which were formed with lipids extracted from Gram-positive B. subtilis than in those from E. coli(p<0.01), however, the effects of GGN4 were not selective in the bilayers formed with lipids from E. coli and red blood cells. Addition of an acidic phospholipid, phosphatidylserine to planar bilayers increased the GGN4-induced membrane conductance(p<0.05), but addition of phosphatidylcholine or cholesterol reduced it(p<0.05). Transmission electron microscopy revealed that GGN4 induced pore-like damages in M. luteus and dis-layering damages on the outer wall of E. coli. Taken together, the present results indicate that the selectivity of GGN4 toward Gram-positive over Gram-negative bacteria is due to negative surface charges, and interaction of GGN4 with outer walls. The selectivity toward bacteria over RBC is due to the presence of phosphatidylcholine and cholesterol, and the trans-bilayer lipid asymmetry in RBC. The results suggest that design of selective antimicrobial peptides should be based on the composition and topology of membrane lipids in the target cells.

• Journal of Preventive Medicine and Public Health
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• v.24 no.3 s.35
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• pp.400-413
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• 1991

The purpose of this paper is to identify factors affecting the optimum mix of required inputs and other relevant factors which account for the variation in physician's productivity in general hospitals, and to find out their implications for the efficient health planning and management. An extended version of Cobb-Douglas production function and cross sectional data of one day patient census from all general hospitals in Korea in 1988 were used in the analysis. Main results of the analysis and their implications could be summarized as follows : (1) The production function for physician's inpatient service shows the evidence of economies of scale, but the production function for physician's outpatient and adjusted-patient service, which combines both out- and in-patient service, shows that of dis-economies of scale. (2) The physician's role for production for all service is smaller than auxiliary personnel's, which imply that more intensive utilization of nurses, nursing aides and other auxiliary personnel is desirable for improving general hospital productivity (3) In case of physician's inpatient and adjusted-patient service, nurses' role is greater than nursing aides'. Therefore, more extensive utilization of nurses is recommended for the efficient operation of general hospitals. (4) The factor of hospital beds plays the leading role among required inputs in the production for physician's in- and adjusted-patient service. (5) The physician's productivity of general hospitals in rural area is lower than that in urban area. And the productivity of teaching hospitals is lower than that of the other hospitals. Further analysis was made in physician production function based upon the size of hospitals, namely those hospitals below 250 beds and those above. Explained variances by the factor of hospital beds was significantly increased in the case of those hospitals above 250. A more detailed and thorough investigation is needed for verifying factors influencing physician's productivity in general hospitals in Korea.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.2
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• pp.61-72
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• 2009

This study aims to analyze the current situation of and issues in the structure of urban neighborhood parks and park facility installation in cities in Gyeonggi-do. Then, based on its findings, plans to improve the space structure of the parks were examined and suggested to raise the city environment improvement function and green area base function of urban parks and fully satisfy users' needs for pleasant rest, recreation and cultural activities. The findings showed that, within parks, the area of grass where access was restricted reached about 24.4% in average. In other words, only 75.6% of total park area could be freely used by park visitors. As for an improvement plan, the grass area where access is limited may be converted into a gras area that can be freely used to raise the park use area, which currently stands only at 75.6%, to 100%. The result of cross analysis through Chi-Square Test regarding lawn use as well as regarding (dis)agreement with reduction of lawn, based on the investigation of cognition, showed a significant agreement of park users with reduction of green areas. Therefore it is considered that lawn space must be reduced according the result of the analysis, to set up plans for facility space that would meet the desires of users. The analysis of user behaviors revealed that many of them used square spaces and walks; therefore it is considered that re-structuring of space is necessary according to local characteristics. This study also made some policy suggestion. urban parks must be a base of city green areas to counter climate changes. When developing a park creation plan, a user demand survey must be conducted in advance. In addition. grass construction methods should be improved to tolerate foot pressure.

• Journal of the Korean Society of Costume
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• v.33
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• pp.5-25
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• 1997

The purpose of this study was to analyze the characteristics of the Junk Art represented in the second half 20the century fashion. The highly developed material civilization resulted in human alienations environmental distruption. By this fact human being of the 20the century was to overcome social com-plexity. In this respect this research was focused that how the characteristics of the junk Art was expressed in the second half 20th century fashion. The concepts of the Junk Art lied in the creation of art work in the 2-dimentional plane of 3-dimentional space through the application of all junks (wood pieces industrial debris trash ready-made goods etc) cast by the mod-ern industrial society and the mass production system. Juck Art had been further envigorated in the footstep of the development of the collage method based on the creation of object aes-thetics. And junk artists have untitled social environments with art by assembling junks as a way of exploring the material world of cur-rent society and provided infinite possibilities of expressional medium and technique. Above all junk Art has been reflected in the fashion as well as other art. Especially a lot of the fashion design by the use of junks and the expressive image of junks is produced in the 20th century. That is many of fashion designers have always been aware of what is happening in the arts and have always been able to use the dis-coveries and ideas of the artist to help them solve design problems and creat fashion which are new inventive and reflective of their time. The fashion designers of the junk fashion design could be said to have presented much more possibilities and new development for-mulas to modern fashion design and provided a new order of other formative arts. Unlike the negative and destructive punk cyberpunk fashion junk fashion was a positive and optimistic aesthetics. junk fashion that keeps pace with science and the development of technology is devoted to trying to grasp the real form of ultimate re-ality.

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.3
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• pp.77-84
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• 1988

This experiment was conducted to investigate the morphological and structual characters and the dry weight of plant (DW/pl.) concerned vegetational structure of orchardgrass pastures by the times of year, from 1 year to 7 year previous, 1986 through 1980, alternately. This experiment was carried out on the experimental fields of Yonsei University. The results are summarized as follows: 1. Population density (PD) was extremely decreased by the times of year. 2. Pasture productivity was highest at 3 year old pasture, was lowest at 5 year old pasture and was recovered at 7 year old pasture. 3. Recovery of pasture productivity was followed the increase of dry weight of plant (DW/pl.) and number of tillers per plant (NT/pl.). 4. The population density of 7 year old pasture was 14 plants per square meter. 5. The number of tillers per plant (NT/pl.), dry weight of plant (DW/pl.) piant length (PL), and plant size (PS) was frequently showed the highest values by the times of established year. 6. The stubble diameter (DIA), stubble area (SB), plant size (PS), distance between neibour plant (DIS) and leaf alea index (LAI) was increased according to the times of year. 7. The dry weight of plant (DW/pl.) was positively significant correlations with the number of tillers per plant (NT/pl.) all of the established pastures, but the dry weight of a tiller (WT) was tended to increase of correlations with the dry weight of plant (DW/pl.) by the times of year. 8. Differences between morphological and structual characters was recognized according to the times of year.

• Journal of the Korean Geographical Society
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• v.41 no.2 s.113
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• pp.227-243
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• 2006

This paper reviews how electronic media technologies involve and produce time-space dimensions in geometrical spaces, focusing on four theoretical perspectives: van Dijk's dual structure of networks as scale extension and reduction; Latour's actor-networks as fluid and hybrid networks; Virilio's dromospherical time as global media vectors; and Castells' timeless time as non-sequential flows. In these four theoretical perspectives, we can see that electronic media technologies involve different and multiple time-space dimensions in geometrical media spaces: from the two-dimensional spaces (surfaces) of concentric circles, through the one-dimensional spaces (lines) of actor-networks to the zero-dimensional spaces (points) of dromospherical time and finally to the multi-dimensional spaces (hypertexts) of timeless time. The paper concludes by suggesting that we need to explain electronic media spaces not only in terms of geometrical media spaces but also in terms of geographical media spaces in order to understand the ways in which electronic media spaces are dis/embedded in geographical spaces.

• YAKHAK HOEJI
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• v.41 no.1
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• pp.48-59
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• 1997

Sustained release matrix tablets, pellets, and coated pellets for the delivery of sulindac were prepared using cellulose derivatives at various ratios, and evaluated for the dis solution pattern. The release of sulindac, from matrix tablets prepared with low viscosity HPMC was relatively fast, and especially the tablets made of Metolose SM released all of sulindac within 1 hr. The release of drug from tablets made of other HPMC derivatives were retarded in the order of the following: Pharmacoat 645>Pharmacoat 606>Pharrnacoat 606+HPC-L>HPC-L. The most sustained release pattern was observed with the preparation of high viscous polymer. Metolose 90 SH. While release of sulindac, from matrix type pellet containing 10mg/cap of Metolose 90 SH or 60 SH was completed within 1 hr, a prolonged release formulation (30% in 1 hr) was obtained by the inclusion of EC. Pellets coated with HPMC showed a fast release pattern (${\geq}$ 80% within 2 hrs), whereas pellets coated with HPMC and EC (molar ratio 1 : 1) showed a sustained release pattern (${\geq}$ 80% in 12 hrs), vath the release from EC pellets being the most sustained. Fast (naked) and slow release pellets coated with EC, Metolose 60SH 50cps and propylene glycol. and enteric pellets coated with HPMCP 55 and Myvacet$^{\circledR}$ were prepared, and combined at various ratios for the assessment of dissolution pattern. The result indicates the possibility that the development of 24 hr sustained release delivery systems containing sulindac for oral administration could be achieved by means of combining sustained and fast release pellets at a proper portion.

• The Journal of Internal Korean Medicine
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• v.12 no.1
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• pp.114-122
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• 1991

Hypertension is not the name of disease but that of syndrome, about which the record of causes and treatments did not exist in the classics. So I surveyed the oriental medical category of hypertension in the classics and studied on the causes and principal acupuncture points of treatment in the modern literature. And a result, I came to the following conclusion. 1. According to the category of hypertension in oriental medicine way, WIND(風), FIRE(火), PHLEGM(痰) were the evoked causes of hypertension. And the greater oart of hypertension's line in the classics was related to DIZZINESS(眩暈), APOPLEXY(中風), WIND OF THE LIVER(肝風). 2. There were exceedingly various causes such as inheritance, mind, emotion, change of nerve, other disease, etc. 3. In the treatment of acupuncture and moxibustion, there were Zusanli(足三里), Quchi(曲池), Fengchi(風池), Baihui(自會), Hegu(合谷), Sanyinjiao(三陰交), Taichong(太衝) which, 7 acupuncture points, showed high ratio. 4. According to the evoked causes, the major acupuncture points became to be different as follow; FIRE(火) : Neiguan(內關 ; P6) WIND(風) : Fengchi (風池 ; G20), Yanglingquan (陽陵泉 ; G34), Taichong(太衝 ; Liv3) PHLEGM(痰) : Zusanli(足三里 ; S36); Sanyinjiao(三陰交 ; Sp6). Basing on the Literature research, I have studied hypertension. I found that there were objective studies on the causes. But I couldn't find any objective study on the category of hypertension in oriental medicine way and the treatment of acupuncture and moxibustion. So I think that more profound study on the category and the interrelation between the acupuncture points of treatment and its dis tribution of the 14 meridians deserves to be continued from now on.

• Restorative Dentistry and Endodontics
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• v.23 no.1
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• pp.379-390
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• 1998

In endodontic treatment, calcium hydroxide has been used as intracanal medicament. Although calcium hydroxide should be removed thoroughly before permanent root canal filling, no effective method for its removal has been reported. Because of irregularity of root canal walls, root curvatures and anatomic variations, it is insufficient to remove calcium hydroxide from the canal wall only by mechanical instrumentation Considering the chemical effects of irrigants on calcium hydroxide, $Ca^{++}$ dissolving effect from two calcium hydroxide products is investigated, using dis- tilled water, NaOCl, citric acid and EDTA. Vitapex$^{(R)}$ 0.1g and calcium hydroxide 0.03g were dissolved in distilled water, 5% NaOCl, 50% citric acid and 17% EDTA respectively, at 1, 3, 5, 10min. time interval. The solution was filtered using filter paper(pore size $5{\mu}m$) and $Ca^{++}$ concentration was determined by ion chromatography. The result were as follows : 1. Distilled water, NaOCl, citric acid and EDTA abstracted more $Ca^{++}$ from calcium hydroxide than Vitapex$^{(R)}$ except NaOCl 1, 5, 10 time interval. 2. EDTA and citric acid abstracted more $Ca^{++}$ from Vitapex$^{(R)}$ and calcium hydroxide than distilled water or NaOCl. The overall result support the view that water-based calcium hydroxide product is easily removed than oil-based calcium hydroxide product and EDTA, citric acid are more effective in $Ca^{++}$ elution than NaOCl or distilled water.

• Computers and Concrete
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• v.31 no.6
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• pp.513-525
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• 2023

This research presents the experimental and theoretical evaluations on circular steel-fiber-reinforced-concrete (SFRC) columns reinforced by glass-fiber-reinforced-polymer (GFRP) rebar under the axial compressive loading. Test programs were designed to investigate and compare the effect of different parameters on the structural behavior of columns by performing tests. Theses variables included conventional concrete (CC), fiber concrete (FC), steel/GFRP longitudinal rebars, and transversal rebars configurations. A total of 16 specimens were constructed and categorized into four groups in terms of different rebar-concrete configurations, including GFRP-rebar-reinforced-CC columns (GRCC), GFRP-rebar-reinforced-FC columns (GRFC), steel-rebar-reinforced-CC columns (SRCC) and steel-rebar- reinforced-FC columns (SRFC). Experimental observations displayed that failure modes and cracking patterns of four groups of columns were similar, especially in pre-peak branches of load-deflection curves. Although the average ultimate axial load of columns with longitudinal GFRP rebars was obtained by 17.9% less than the average ultimate axial load of columns with longitudinal steel rebars, the average axial ductility index (DI) of them was gained by 10.2% higher than their counterpart columns. Adding steel fibers (SFs) into concrete led to the increases of 7.7% and 6.7% of the axial peak load and the DI of columns than their counterpart columns with CC. The volumetric ratio had greater efficiency on peak loads and DIs of columns than the type of transversal reinforcement. A simple analytical equation was proposed to predict the axial compressive capacity of columns by considering the axial involvement of longitudinal GFRP rebars, volumetric ratio, and steel spiral/hoop rebar. There was a good correlation between test results and predictions of the proposed equation.