• Applied Biological Chemistry
• /
• v.38 no.1
• /
• pp.42-48
• /
• 1995

The experiment was carried out to purify and to investigate the properties of the cyclodextrinase produced from Bacillus megaterium KFCC 11855. The enzyme was partially purified with $(NH_4)_2SO_4$ and chromatography on DEAE-trisacryl, Ultrogel AcA 34, DEAE-trisacryl and Ultrogel HA. The optimum temperature and pH of the purified enzyme were $60^{\circ}C$ and 6.0, respectively. The enzyme was stable at the temperature of $45^{\circ}C$ below and at the pH range of $6.0{\sim}9.0$, respectively. The Km value for ${\gamma}-cyclodextrin$ was 0.903 mM. The enzyme activity was increased by $Mg^{2+}$ and $Mn^{2+}$, but decreased by $Hg^{2+}$ and $Cu^{2+}$. The enzyme degraded ${\gamma}-cyclodextrin$ but not ${\alpha}-cyclodextrin$. The degree of ${\beta}-CD$ degradation by the enzyme was very low. The decomposed products of ${\gamma}-cyclodextrin$ by the enzyme were mainly glucose, maltose and a little amount of maltotriose.

• Journal of Korean Neurosurgical Society
• /
• v.63 no.2
• /
• pp.178-187
• /
• 2020

Objective : The extensive vasa vasorum network functions as a conduit for the entry of inflammatory cells or factors that promote the progression of angiogenesis and plaque formation. Therefore, we investigated the correlation between the carotid vasa vasorum activities and carotid plaque vulnerability using indocyanine green video angiography (ICG-VA) during carotid endarterectomy (CEA). Methods : Sixty-nine patients who underwent CEA were enrolled prospectively from September 2015 to December 2017. During CEA, a bolus of ICG was injected intravenously before and after resecting the atheroma. Additionally, we performed immunohistochemistry using CD68 (a surface marker of macrophages), CD117 (a surface marker of mast cells), and CD4 and CD8 (surface markers of T-cells) antibodies to analyze the resected plaque specimens. Results : The density of active vasa vasorum was observed in all patients using ICG-VA. The vasa vasorum externa (VVE) and interna (VVI) were seen in 11 (16%) and 57 patients (82.6%), respectively. Macroscopically, the VVE-type patterns were strongly associated with preoperative angiographic instability (81.8%, p=0.005) and carotid plaque vulnerability (90.9%, p=0.017). In contrast, the VVI-type patterns were weakly associated with angiographic instability (31.6%) and plaque vulnerability (49.1%). CD68-stained macrophages and CD117-stained mast cells were observed more frequently in unstable plaques than in stable plaques (p<0.0001, p=0.002, respectively). Conclusion : The early appearance of VVE, along with the presence of many microvessel channels that provided nutrients to the developing and expanding atheroma during ICG-VA, was strongly associated with unstable carotid plaques. The degree of infiltration of macrophages and mast cells is possibly related to the formation of unstable plaques.

• The Journal of the Korea Contents Association
• /
• v.18 no.10
• /
• pp.320-334
• /
• 2018

The purpose of this study is to analyze research trends in international development and cooperation on education and to suggest directions for the Korean teachers and teacher education to achieve 'Sustainable Development Goals (SDGs).' The examination of 8 databases resulted in the identification of 2,945 studies, and 6 of these references met the inclusion criteria for systemic review. Major findings revealed that pre- and in-service teachers recognized the necessity of international development education but had a low degree of teacher efficacy. The teachers who participated in ODA education programs have experienced difficulties due to insufficient understanding of local sites and role performance. Then, a couple of studies of mathematics and early childhood education compared the Korean national curriculum and education system with developing countries'. Lastly, it is important to have a sustainable system which promotes all teachers, including retired ones, in global development and cooperation on education. For the successful achievement of SDGs, Korean teachers should develop their expertise, a deep understanding of partner countries, and stable quality education for the underprivileged.

• Korean Journal of Soil Science and Fertilizer
• /
• v.42 no.3
• /
• pp.145-151
• /
• 2009

This study was conducted to develop rational soil management and enhance the productivity of lands converted from paddy soils. Specifically, the changes in the soil physical properties brought about by the change in land usage from paddy soil were evaluated. This was carried out from 1999 to 2001 at 50 site in large-scale converted paddy fields of Kimcheon, Youngcheon, Gyeongsan and Milyang in the Youngnam region, categorized according to soil texture and drainage class. The ridge height of converted paddy soils was higher in coarse-textured and poorly-drained soils than in fine-textured and well-drained soils. The gray color of the surface soil was of lesser degree in converted soils than paddy soils and more notable in welldrained soils. The porosity ratio and the formation of aggregate structure were higher, and the appearance of soil mottling was deeper in converted paddy fields than in paddy soils. The glaying layer "g" of surface soil degraded with time. The porosity and amount of water stable aggregate was found to increase with time after conversion. The penetration resistance of the converted paddy soil was lower and deeper with time after conversion. The soil aeration of the converted paddy soil was lower in sandy loam than in loamy soil. Furthermore, soil aeration was influenced by ridge height and drainage class in poorly-drained soils.

• The Korean Journal of Ecology
• /
• v.24 no.2
• /
• pp.101-109
• /
• 2001

We created an environmental forest on the basis of ecological design around the incineration plant of Jindo Engineering and Construction Co., Ltd., which is located in Jeongwang-dong, Siheung-si, Kyunggi-do. To get ecological information of this site, physico-chemical properties of soil on salt marsh, which is located close to the syudy site and of forest soil transported from other sites for ecological restoration were analyzed. Texture of salt marsh and transported soils were loam and sandy loam, respectively. pH, organic matter, T-N, available P, and exchangeable K and Na contents of salt marsh and transported forest soils were 6.7 and 5.4, 4.1 and 0.4%, 1.0 and 0.3mg/g, 46.7 and 6.8ppm, 521 and 207ppm, and 3.8 and 0.5mg/g, respectively. Introduced plants were selected among the dominant species of forests and the species composing the potential natural vegetation around the present study site. Those plants were selected again by considering the tolerances to air pollution and to salt, and their availability. Selected trees were Pinus thunbergii, Sophora japonica, Celtis sinensis, Quercus aliena, Q. serrata, Q. dentata, and Q. acutissima. Selected sub-trees were Albizzia julibrissin, Koelreuteria poniculata, and Styrax japonica and shrubs were Rhododendron yedoense var. poukhanense, R. mucronulatum, Callicarpa japonica, Euonymus alatus, E. japonica, and R. schlippenbachii. On the other hand, introduction of herbs was not considered except for Liriope platyphylla, which was ornamentally planted in one site. Planting bed of mound type was adopted to provide the fine drainage system. Mound was designed to furnish litter, A, B, and C layers simuating the profile of forest soil. Slope of mound was mulched by rice straw of 2cm in thickness to prevent for sliding of litter and soil in cases of strong wind or heavy rain. Height of mound was designed to secure more than 1 m by combining A and B layers. Narrow zones, in which mound with stable slope degree cannot be prepared, was designed to equip the standard soil depth with the introduction of stone for supporting. On the other hand, plants with shallow root system were arranged in some zones, in which satisfactory soil depth cannot be ensured. Plants were arranged in the order of tree, sub-tree, and shrub from center to edge on the mound to make a mature forest of a dome shape in the future. Dispersion of plants was designed to be random pattern rather than clumped one. Problems on creation of the environmental forest by such ecological design were found to be management or inspection by non-specialized project operators and inspecting officers, and regulations for construction without ecological background. Alternative plans to solve such problems were suggested.

• Journal of Korean Society of Forest Science
• /
• v.99 no.6
• /
• pp.855-862
• /
• 2010

The objectives of this study were to analyze vegetation types and stand structures of the red pine (Pinus densiflora) in Kangwon southern region for stable and sustainable forest management. The pine forests in study sites were classified into 4 communities, 2 groups, so total 6 vegetation units. Species with high constance degree were Quercus mongolica, Rhus trichocarpa, Lindera obtusiloba, Lespedeza maximowiczii, Quercus serrata, Spodiopogon sibiricus, Aster scaber and Fraxinus sieboldiana. In the importance value(I.V.) analysis of each layer, P. densiflora showed highly in tree layer while in other layers competitive broad-leaved species such as Quercus spp. were high. P. densiflora also showed large size of DBH, while broad-leaved species distributed middle and small DBH. The annual ring growths of P. densiflora and competitive broadleaved species were variable according to area, site condition, tree year and species, it is considered that appropriate silvicultual practice methods should be employed to remove rival broad-leaved species for maintenance of sustainable red pine forests considering the characteristics of each stand.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.2 no.2
• /
• pp.69-77
• /
• 1997

A 12-cm long sediment core was collected from a station in Lake Shihwa where high salinity-anoxic deep water is isolated from low salinity-oxic surface water by a strong halocline barrier. Unprecedented concentrations of porewater ammonia and lead are encountered: at 9 cm sediment depth ammonia builds up to 1420 ${\mu}M$ and at 3 cm lead to 1348 nM. As they are stable in anoxic condition, high concentrations of ammonia and lead suggest a development of notorious anoxic condition in the benthic environment of the lake. The degree of pollution of the deep water is likely to be directly proportional to the magnitude of benthic flux, because the deep water is isolated from the surface water by the halocline. Apparent coincidence of the ammonia residence time in the deep water with the elapsing time after the completion of the artificial lake construction, as about three years, suggests that the deep water pollution is being progressed entirely by benthic flux at least with respect to ammonia. The residence time for lead is such a short 20 days that it suggests a rapid return of the bottom water lead, which is originated from porewater by benthic flux, back to sediments probably as metal sulfide phases. The speculation on the return of lead as sulfide phases is likely to be supported by high concentration of hydrogen sulfide in the deep water and by high sinking rate of non-organic particles in Lake Shihwa.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.264-264
• /
• 2017

Legumes are good sources of various nutrients. Among legumes, soybean and its flour are accessible foods to consumers. However, in case of soybean flour, there is a disadvantage of easily going rancid. Thus, this study aimed to investigate how the quality of soybean flour changes during storage according to the packaging materials and storage temperatures. The raw and roasted soybean flours were packed in two types of packaging, polyethylene (PE) and polypropylene (PP) film bags respectively, and stored at three different storage temperatures (4, 20, and $45^{\circ}C$) for 1 year. The acid value, conjugated diene value, peroxide value, p-anisidine value, thiobarbituric acid (TBA) value, lipoxygenase activity, and fatty acid content of raw and roasted soybean flours were measured at the point of starting storing, and after 1, 2, 4, 8, and 12 weeks of storage. The acid value of soybean flour was increased for 4 weeks and thereafter significantly decreased (p < 0.0001). The conjugated diene value was significantly increased after 4 weeks storage at $45^{\circ}C$ with PE and PP film bags (p < 0.0001). The peroxide value had no changes during 4 weeks storage at $45^{\circ}C$ with PE and PP film bags, and then those was dramatically increased after 8 weeks (p < 0.0001). The p-anisidine values in all of storage conditions were decreased after 4 weeks. Lipoxygenase activity was decreased at 12 weeks storage at $20^{\circ}C$ and $45^{\circ}C$ with PP film bags. Acid value had positive correlations with p-anisidine value (r = 0.30 and p < 0.0001) and lipoxygenase activity (r = 0.36 and p < 0.0001), and had negative correlations with conjugated diene value (r = -0.45 and p < 0.0001) and peroxide value (r = -0.25 and p < 0.001). Conjugated diene value had a high positive correlation with peroxide value (r = 0.76 and p < 0.0001), but that had a negative correlation with lipoxygenase activity (r = -0.51 and p < 0.0001). Peroxide value had negative correlations with p-anisidine value (r = -0.20 and p < 0.01) and TBA value (r = -0.15 and p < 0.05). The degree of reduction in fatty acid content of raw soybean flour was higher than the roasted soybean flour during the storage. Total fatty acid content had positive correlations with acid value (r = 0.45 and p < 0.0001) and p-anisidine value (r = 0.58 and p < 0.0001), but had a weak negative correlation with conjugated diene value (r = -0.19 and p < 0.01). This study showed how the rancidity of the raw and roasted soybean flours progressed during storage. Thus, our findings can be used as base data to do a further study of finding and developing more stable storage conditions of the soybean flour.

• Journal of Energy Engineering
• /
• v.25 no.4
• /
• pp.176-183
• /
• 2016

This study relates to a polymer electrolyte membrane for improved performance fuel cell, were researched with respect to properties required for driving a fuel cell. The bis(4-fluorophenyl)phenyl phosphine oxide was sulfonated using fuming sulfuric acid. Synthetic hydrophilic oligomer and the hydrophobic oligomer and the block copolymers were prepared via aromatic nucleophilic substitution polycondensation. A block copolymer structure and degree of sulfonation was analyzed by $^1H$-NMR and gel permeation chromatography(GPC) analysis. Thermal stability was confirmed by thermogravimetric analysis(TGA), block copolymer was stable at high temperature(>$200^{\circ}C$), The ion conductivity was measured in order to demonstrate the performance of fuel cell. Synthesis membrane was the increase of temperature was improved conductivity up to 58 mS/cm due to the influence of the developed ion clusters. The phase separation of the polymer was observed to make AFM analysis.

• Radiation Oncology Journal
• /
• v.32 no.4
• /
• pp.231-237
• /
• 2014

Purpose: To evaluate the predictive value of the early response of $^{18}F$-flurodeoxyglucose positron emission tomography (FDG PET) during concurrent chemoradiotherapy (CCRT) for locally advanced non-small cell lung cancer (NSCLC). Materials and Methods: FDG PET was performed before and during CCRT for 13 NSCLC patients. Maximum standardized uptake value ($SUV_{max}$), mean standardized uptake value ($SUV_{mean}$), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured and the changes were calculated. These early metabolic changes were compared with the standard tumor response by computed tomograms (CT) one month after CCRT. Results: One month after the completion of CCRT, 9 patients had partial response (PR) of tumor and 4 patients had stable disease. The percent changes of $SUV_{max}$ ($%{\Delta}SUV_{max}$) were larger in responder group than in non-responder group ($55.7%{\pm}15.6%$ vs. $23.1%{\pm}19.0%$, p = 0.01). The percent changes of $SUV_{mean}$ ($%{\Delta}SUV_{mean}$) were also larger in responder group than in non-responder group ($54.4%{\pm}15.9%$ vs. $22.3%{\pm}23.0%$, p = 0.01). The percent changes of MTV ($%{\Delta}MTV$) or TLG ($%{\Delta}TLG$) had no correlation with the tumor response after treatment. All the 7 patients (100%) with $%{\Delta}SUV_{max}{\geq}50%$ had PR, but only 2 out of 6 patients (33%) with $%{\Delta}SUV_{max}$ < 50% had PR after CCRT (p = 0.009). Likewise, all the 6 patients (100%) with $%{\Delta}SUV_{mean}{\geq}50%$ had PR, but only 3 out of 7 patients (43%) with $%{\Delta}SUV_{mean}$ < 50% had PR after CCRT (p = 0.026). Conclusion: The degree of metabolic changes measured by PET-CT during CCRT was predictive for NSCLC tumor response after CCRT.