• Journal of Periodontal and Implant Science
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• v.31 no.1
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• pp.1-23
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• 2001

Chitosan is biodegradable natural polymer that has been demonstrated its ability to improve wound healing, and calcium metaphosphate(CMP) is a unique class of phosphate minerals having a polymeric structure. In this study, chitosan/CMP and platelet derived growth factor(PDGF-BB) loaded chitosan/CMP sponges were developed, and the effect of the sponges on bone regeneration and their possibility as scaffolds for bone formation by three-dimensional osteoblast culture were examined. PDGF-BB loaded chitosan/CMP sponges were prepared by freeze-drying of a mixture of chitosan solution and CMP powder, and soaking in a PDGF-BB solution. Fabricated sponge retained its 3-dimensional porous structure with $100-200\;{\mu}m$ pores. The release kinetics of PDGF-BB loaded onto the sponge were measured in vitro with $^{125}I-labeled$ PDGF-BB. In order to examine their possibility as scaffolds for bone formation, fetal rat calvarial osteoblastic cells were isolated, cultured, and seeded into the sponges. The cell-sponge constructs were cultured for 28 days. Cell proliferation, alkaline phosphatase activity were measured at 1, 7, 14 and 28 days, and histologic examination was performed. In order to examine the effect on the healing of bone defect, the sponges were implanted into rat calvarial defects. Rats were sacrificed 2 and 4 weeks after implantation and histologic and histomorphometrical examination were performed. An effective therapeutic concentration of PDGF-BB following a high initial burst release was maintained throughout the examination period. PDGF-BB loaded chitosan/CMP sponges supported the proliferation of seeded osteoblastic cells as well as their differentiation as indicated by high alkaline phosphatase activities. Histologic findings indicated that seeded osteoblastic cells well attached to sponge matrices and proliferated in a multi-layer fashion. In the experiments of implantation in rat calvarial defects, histologic and histomorphometric examination revealed that chitosan/CMP sponge promoted osseous healing as compared to controls. PDGF-BB loaded chitosan/CMP sponge further echanced bone regeneration. These results suggested that PDGF-BB loaded chitosan/CMP sponge was a feasable scaffolding material to grow osteoblast in a three-dimentional structure for transplantation into a site for bone regeneration.

• Korean Journal of Environment and Ecology
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• v.18 no.3
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• pp.306-315
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• 2004

Yangjae stream, stretching through Seocho-gu and Gangnam-gu, is a representative city stream with its environmentally friendly stream makeover project model, launched in 1995. The district of Gangnam-gu, the subject of this study, is under high pressure from the residents for its use as a huge residential areas close to the stream. The study has two main purposes. The first is to identify the condition and characteristic of utilization of Yangjae stream which is currently being increased in use by the stream restoration. Secondly, the study aims to suggest the environment-friendly management to accomplish arrangement of the naturally friendly stream based on the identification survey, The result from the user survey with 303 valid answer sheets show that the people from neighboring residential areas use this stream a lot doing exercising(51.8%) and taking a walk(24.4%) in their free time. Also regular use rate is high, and people are likely to use it alone(30.4%) or as a family(28.4%). With regard to the need of facility increase, even though the respondents required resting places in the shade(80.8%) most, overall, additional introduction of facilities was analyzed as unnecessary(78.8%). safety issue(22.0%) and a lack of convenience facilities(17.6%) and resting places in the shade(16.6%) are pointed as main problems while the users are generally satisfied(59.5%) with the stream. Improving walk-way and planting trees for shade on the slope were designed as a solution for these problems. For securing safety through improvement of walk-way, the scattering of pressure of current walk with building new walk using berms was presented. In order to increase safety on the walk-way(see above figure), the study proposes to build a new walk-way with berms to disperse excessive pressure. It also suggests the tree planting to provide shade in the stream and to make a provision for the planting of forest trees in the current law.

• Journal of the Korean Geographical Society
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• v.50 no.3
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• pp.255-276
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• 2015

This paper presents a multi-agent system model of land-use and cover changes, which is developed and applied to the Gariwang-san and its vicinity, located in Pyeongchang and Jeongseon-gun, Gangwon province, Korea. The Land Use Dynamics Simulator (LUDAS) framework of this study is well suited for representing the spatial heterogeneity and dynamic interactions between human and natural environment, and capturing the impacts of forest-opening policy interventions to future socio-economic and natural environment changes. The model consists of four components: (1) a system of human population, (2) a system of landscape environment, (3) decision-making procedures integrating human(or household), environmental and policy information into forest land-use decisions, and (4) a set of policy scenarios that are related to the forest-opening. The results of model simulation by different combination of various forest management scenarios are assessed by the levels of household income, ecosystem service value and income inequality in the study region. As a result, the optimal scenario of forest-opening policies in the study region is to open the forest to local residential community for the purpose of recreation, considering the distinctive topographical feature. The model developed in this research is expected to contribute to a decision support system for sustainable forest management and various land-use policies in Korea.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.4
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• pp.671-676
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• 2008

AgI/II of Streptococcus mutans(S. mutans) is an important virulence factor that contributes to the pathogenesis of S. mutans-induced dental caries. In oral cavity, salivary IgA antibodies act as safeguards against enormous challenges from oral bacteria. IgA antibodies inhibit adherence of cariogenic microorganisms to hard surfaces. Analysis of salivary IgA against AgI/II can be very useful diagnostic and powerful communication tools to the dental caries The purpose of this study was to investigate correlation between salivary AgI/II specific IgA and incidence of dental caries among children and young adults. Subjects consisted of 28 children and 18 adults. They were assigned to four groups : Group I deft index $\leq$3), Group II(deft index $\geq$4), Group III(DMFT index $\leq$3), Group IV(DMFT index $\geq$4) and they was divided two groups into caries resistant group and caries susceptible group. The study group were examined caries activity and their salivary IgA was evaluated by enzyme-linked immunosorbent assay. The results are as follows : 1. There was a positive correlation between the number of S. mutans and caries activity. 2. The titer of salivary IgA against the AgI/II was significantly higher in caries resistant group than caries susceptible group(p<0.01). 3. The titer of salivary IgA against the AgI/II in Group III was significantly higher than Group II(p<0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.1
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• pp.54-60
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• 2003

This study evaluated the influence of chemomechanical caries removal agent $Carisolv^{TM}$(MediTeam, Sweden) for composite resin adhesion to sound human permanent and primary dentin. The buccal/labial surfaces of 80 permanent molars and 80 primary incisors were used. Four types of adhesives and one composite resin were used; AQ Bond(Sun Medical, Japan), Clearfil SE Bond(Kuraray, Japan), Single Bond(3M, USA), Scotchbond Multi-Purpose(3M, USA) and Z100(3M, USA). One drop of $Carisolv^{TM}$(MediTeam, Sweden) was pretreated on the dentin for 0 second(control) and 60 seconds. The specimens were thermocycled for 1,000 times in baths kept 5 degrees C and 55 degrees C with a 30 seconds dwell time. Shear bond strengths were tested and the data was statistically analyzed using one-way ANOVA with subsequent post hoc Scheffe test at p<0.05. $Carisolv^{TM}$ treatment significantly decreased the shear bond strength. Shear bond strength of permanent dentin was significantly higher than that of primary dentin. Clearfil SE Bond treatment groups showed the highest shear bond strength and AQ Bond treatment groups showed the lowest shear bond strength.

• Journal of Mushroom
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• v.13 no.3
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• pp.212-216
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• 2015

A new commercial strain "Mongdol" of oyster mushroom was developed by hyphal anastomosis. It was improved with hybridization between monokaryotic strain derived from Pleurotus ostreatus ASI 0627 and dikaryotic strain derived from P. ostreatus ASI 2929. The optimum temperature of mycelial growth and fruiting body development were $25{\sim}30^{\circ}C$ and $12{\sim}18^{\circ}C$, respectively. When two different media including PDA (potato dextrose agar medium) and MCM (mushroom complete medium) were compared, the mycelial growth of this mushroom was faster in MCM than in PDA. Similar result was observed with the control strain P. ostreatus ASI 2504. Analysis of the genetic characteristics of the new cultivar "Mongdol" showed a different DNA profile as that of the control strain ASI 2504, when RAPD (Random Amplified Polymorphic DNA) primer URP3 and URP6 were used. Fruiting body production per bottle was about 106 g using demonstration farms. The color of pileus was blackish gray and the stipe was long. Therefore, we expect that this new strain "Mongdol" will satisfy the consumer's demand for high quality mushrooms.

• Journal of Oriental Neuropsychiatry
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• v.6 no.1
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• pp.19-39
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• 1995

In order to compare the anti-stress effect of Guibitang with that of ascorbic acid, after these medicines were administered to guinea pigs induced by heating and swimming stress, the changes of the weight of body and organ, and content of plasma catecholamines, serum total cholesterol, free cholesterol, triglyceride, protein, glucose and cortisol were measured. The results were as follows : 1. The weight of the body was increased with statistical significance in the groups administered ascorbic acid and ascorbic acid with Guibitang as compared with in the group administered non ascorbic acid on both heating and swimming stress. 2. The weight of spleen decreased with statistical significance in the groups administered ascorbic acid, Guibitang and ascorbic acid with Guibitang as compared with in the group administered non ascorbic acid on heating stress, but in case of swimming stress, the weight of spleen decreased with statistical significance in the groups administered ascorbic acid and ascorbic acid with Guibitang as compared with in the group administered non ascorbic acid. The weight of adrenal decreased with statistical significance in the groups administered ascorbic acid and ascorbic acid with Guibitang as compared with in the group administered non ascorbic acid on heating stress alone. 3. Plasma norepinephrine content decreased with statistical significance not only in the groups administered ascorbic acid and ascorbic acid with Guibitang as compared with in the group administered non ascorbic acid but in the group administered ascorbic acid with Guibitang as compared with in the group administered ascorbic acid on heating stress. In case of swimming stress, norepinephrine decreased with statistical significance in the groups administered ascorbic acid, Guibitang and ascorbic acid with Guibitang as compared with in the group administered non ascorbic acid. 4. Plasma dopamine content decreased with statistical significance only in the group administered ascorbic acid and ascorbic acid with Guibitang as compared with in the group administered non ascorbic acid on both heating and swimming stress. 5. Serum total cholesterol content decreased with statistical significance in the groups administered ascorbic acid with Guibitang as compared with in the group administered non ascorbic acid on heating stress, but in case of swimming stress, it decreased with statistiscal significance only in the group administered ascorbic acid with Guibitang as compared with in the group administered non ascorbic acid. 6. Serum triglyceride content decreased with statistical significance not only in the groups administered ascorbic acid, Guibitang and ascorbic acid with Guibitang as compared with in the group administered non ascorbic acid but in the group administered ascorbic acid with Guibitang as compared with in the group adminstered ascorbic acid on heating stress. In case of swimming stress, triglyceride decrease with statistical significance only in the group administered ascorbic acid with Guibitang as compared with in the group administered non ascorbic acid. 7. Serum glucose content increased with statistical significance in the groups administered Guibitang and ascorbic acid with Guibitang as compared with in the group administered non ascorbic acid on both heating and swimming stress, particulaly in case of swimming stress, in the group administered ascorbic acid with Guibitang, it increased with statistical significance as compared with in the group administered ascorbic acid. 8. Serum cortisol content decreased with statistical significance only in the group administered ascorbic acid and ascorbic acid with Guibitang as compared with in the group administered non ascorbic acid on heating stress.

• Korean Journal of Pharmacognosy
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• v.40 no.3
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• pp.196-204
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• 2009

This study was carried out to investigate the in vivo and in vitro inhibitory effect of a traditional herbal complex (HC) extract prepared from a mixture of four oriental herbs (Dioscorea Rhizoma, Glycine soja Sieb. et Zucc, Bombycis corpus, Fermented Glycine soja) that have been widely used for the treatment and prevention of diabetes mellitus on hyperglycemia. The water extract of HC showed potent inhibitory effect on $\alpha$-glucosidase with $IC_{50}$ value of 1.24 mg/mL. Additionally, the ethanol extract of HC was also found to exhibit significant inhibitory effect against protein tyrosine phosphatase $1{\beta}$ ($PTP1{\beta}$), which is known as a major regulator of both insulin and leptin signaling. In the $PTP1{\beta}$ inhibitory assay, the most active n-hexane fraction obtained from the ethanol extract of HC, was identified as a mixture of fatty acid derivatives by gas chromatography-mass spectrometry (GC-MS). In high-fat diet-low dose streptozotocin (STZ)-induced diabetic rat, the water extract of HC improved the oral glucose intolerance as compared with rosiglitazone. HC also caused a marked decrease of body weight and fasting blood glucose and a significant improvement on glucose tolerance in metabolic syndrome mice model. These findings support that this traditional HC may be useful in the control of blood glucose in diabetes mellitus and metabolic syndrome.

• The Korean Journal of Malacology
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• v.25 no.2
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• pp.105-112
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• 2009

We investigated the degree of obesity, histological development stages of gonads and sexual maturation induction rates of comb pen shell, Atrina pectinata, per the type of micro-algae supplied. Terms of maturation by singular or mixed supply of microalgae, it was found that maturation of the female was the quickest at 60.0% by the Tetraselmis tetrathele (Tet). experiment group followed by 57.1% by the Chlorella ellipsoidea (Chl). experiment group and 16.7% by the Phaeodactylum tricornutum (Pha). experiment group. However, there were no significant differences between Tet. experiment group and Chl. experiment group. As for the male, maturation was the quickest at 60.0% by the Tet. experiment group followed by 16.7% by the Chl. experiment group and 14.3% by the Pha. experiment group. In light of these results, Tet. is concluded to be a very useful feed organism in breeding the mother comb pen shells. Upon completion of the experiment, the sexual maturation induction rate for the female was found to be the highest at 82.0% in the Tet. experiment group followed by 72.0% by the Chl. experiment group, 64.0% by the Pha. experiment group and 58.0% by the mixed micro-algae experiment group. During the period of experiment, the survival rate was the highest at 94.4% by the mixed micro-algae experiment group followed by 90.0% by the Pha. experiment group, 83.1% by the Tet. experiment group and 78.8% by the Chl. experiment group.

• The Journal of Engineering Research
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• v.3 no.1
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• pp.199-205
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• 1998

Cullet Quality Control in auto glass bottle factory is the most important in recent days because of the increasing cost of materials in glass bottle. Since the composition of plate glass cullet is similar, the cullet quality using plate cullet in glass bottle factory is easily controlled. In addition to this, the price of plate glass cullet is so low that the cost reduction can be achieved. If the ratio of plate glass cullet and gush is over 25%, the liquidity of glass water become worse, which is caused by different compositions and viscosity of the components. As a results, Furnace bottom temperature becomes low and glass water becomes inhomogeneous. Thus production efficiency of glass bottle becomes low because of increasing devitrification in Dead Corner part in glass melting furnace. Three experimental methods – (1) increasing melting temperature, (2) using Booster, (3) using bubbler – were performed to increase the furnace bottom temperature and glass water homogeneity. The amounts of plate glass cullet was able to increase up to 90%, 70% and 60% without any devitrification using booster, bubbler and the method of glass melting temperature increase from $1480^{\circ}C$ to $1560^{\circ}C$ respectively. It is not possible to increase the glass melting temperature without the reduction of furnace operation time and the increase of fuel cost. The booster process has disadvantage of much electric energy consumption. Since the bubbler process uses physical convection of melting glass based on compression air, the homogeneity of molten glass is not so good as that of booster process but it can reduce the cost of glass bottle.