• Journal of Oral Medicine and Pain
• /
• v.34 no.1
• /
• pp.23-37
• /
• 2009

The antibacterial effect of phytoncide on Porphyromonas gingivalis, which is the main causative agent of periodontal disease and halitosis, has been reported. However, little is known about its effect on normal oral microflora. The present study was performed to observe the effect of phytoncide on oral normal microflora and the inhibitory effect of surviving resident oral bacteria on P. gingivalis. In this study, saliva from each of 20 healthy subjects was treated with 1% phytoncide from Japanese Hinoki (Chamaecyparis obtusa Sieb. et Zucc.). Surviving salivary bacteria were isolated on blood agar plates and identified by 16S rDNA sequencing. In order to select inhibitory isolates against P. gingivalis, the isolates from the phytoncide-treated saliva were cultured with P. gingivalis. The results were as follows: 1. In general, the number of bacteria in saliva from periodontally healthy subjects was decreased when the saliva was treated with 1% phytoncide. 2. The majority of the salivary bacteria surviving the treatment of phytoncide were S. thermophilus (53%). 3. Most of the surviving salivary bacteria (72.5%) inhibit the growth of P. gingivalis A7A1-28 and P. gingivalis W83 on blood agar plates. 4. Among the surviving S. thermophilus, 85.8% of them were observed to inhibit P. gingivalis strains and 75.8% of the surviving S. sanguinis were inhibitory. Taken together, oral resident bacteria surviving phytoncide, which has been shown to inhibit P. gingivalis, may exert an additional inhibitory activity against the periodontopathic bacterium. Therefore, phytoncide can be used for preventing and ceasing the progress of periodontal disease and halitosis, and thus is expect to promote oral health.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.18 no.2 s.117
• /
• pp.126-135
• /
• 2007

This paper proposes a new miniaturization method for a parallel coupled line filter with enhanced bandwidth characteristics. A previous method incorporated several advantages, such as size reduction through the use of only a small number of capacitors, in addition to grounding, suppression of harmonic characteristics, and improved skirt characteristics for the parallel coupled line filter, which is conventional in the field of RE filters due to its design and fabrication simplicity. However, the previous method also has disadvantages related to the bandwidth shrinkage of the miniaturized filters. In this paper, the amount of bandwidth shrinkage is analyzed in terms of the relationship between the loaded Q(quality factor) and the group delay of a resonator. Moreover, the reduction in the bandwidth is solved by a design with new design equations. To show the validity of the proposed method, a hairpin filter with a center frequency of 5.2 GHz and an fractional bandwidth(FBW) of 10% was scaled down to half its original dimension by the proposed method with the enhanced bandwidth characteristics. The measured result shows a high level of agreement with theoretical results.

• Korean Journal of Environmental Agriculture
• /
• v.26 no.2
• /
• pp.149-158
• /
• 2007

The objective of this study were to offer a basis data for application of management of forest resources through grasping of species composition by layer of forest vegetation in the Mt. Geumwon recreational forest. The tree and subtree layer consisted of 27 and 44 species in Mt. Geumwon recreational forest respectively. The importance value of Quercus mongolica (57.1) and Q. serrata (40.4) were highest in the tree layer and that of Acer pseudo-sieboldianum (43.4) was highest in the subtree layer, respectively. The shrub and herb layer was composed of 71 and 69 species, respectively. The value of species diversity ranged from 1.0391 to 1.5403. Evenness ranged from 0.7259 to 0.8320. Dominance was 0.2741 at tree layer, 0.2440 at subtree layer, 0.1680 at shrub layer, and 0.1702 at herb layer, which showed that Mt. Geumwon recreational forest is dominated by a large number of species at all layer. The result of forest vegetation in Mt. Geumwon recreational forest may be utilized as a basic data for application of reasonable ecological management of forest resources.

• Journal of the Korean Data and Information Science Society
• /
• v.27 no.5
• /
• pp.1375-1387
• /
• 2016

The purpose of this study was to evaluate the effect of exercise on cognitive function in the elderly through a systematic literature review and meta-analysis. For the study purpose, 14 studies were selected through a systematic process of using several databases and 11 studies were used to estimate the effect size of exercise on cognitive function. Meta-analysis was performed using a random effects model, and the effect size on cognitive function was calculated. The effect size for cognitive function of exercise intervention was Hedges' g=1.05 (95% CI: 0.61~1.50), indicating a large effect size. For heterogeneity, moderator analysis was performed using intervention, number of times per week, intervention duration, and cognitive function measurement. Cognitive function measurement was statistically significant, the other moderators did not significant difference. Results support that exercise has significant positive effects on cognitive function in elderly in korea. It also provided a basis that can be applied to exercise intervention design for cognitive function.

• Journal of Korean Society of Forest Science
• /
• v.77 no.3
• /
• pp.315-321
• /
• 1988

To investigate and analyze the change in the forest community structure between non-attacked time(in 1980) and severly damaged time(in 1987) by pine gall midge, Thecodoplosis japonensis, four plots with five subplots were sampled at Cheongwon-gun of Chungcheungbuk-do. The total number of woody species per 0.2ha changed 32 in 1980 to 53 in 1987. According to the damage increasing, the importance value of the genus Quercus as a substituting species has sprung up. Especially the importance value of Quercus serrata and Q. aliena singnificantly increased in the heavily insect infested forest. As to changes of forest community structure during 7 years, diversity of investigation structure has increased. The similarity indices between 1980 and 1987 were 52.9% and 49.7% in the understory and shrub stratum, respectively.

• Korean Journal of Biological Psychiatry
• /
• v.13 no.4
• /
• pp.260-266
• /
• 2006

Objectives : Synapsin III near VCFS region on chromosome 22q affects. It could be an interesting candidate gene for schizophrenia. D22S280 is a highly polymorphic genetic marker residing in synapsin III. We examined association of D22S280 marker on synapsin III with Korean patients with schizophrenia. Methods : The subjects were 46 male Korean patients with schizophrenia and 60 male normal controls. Using polymerase chain reaction, gel electrophoresis, ABI 310 genetic analyzer, and GeneScan Collection 3.1 software, we confirmed genotypes of D22S280 marker. We examined Hardy-Weinberg equilibrium and case-control association using SAS/Genetic 9.1.3. Results : Genotypes of both schizophrenia and control groups were in Hardy-Weinberg equilibrium. We could not find any significant statistical differences in allele-wise(${\chi}^2$=10.4, df=6, p=0.098) and genotype-wise (${\chi}^2$=22.1 df=19, p=0.258) analyses of D22S280 marker between schizophrenia and normal controls. Individual allele analyses with df=1 showed significant differences in A1(p=0.025) and A7(p=0.034) allele, which were not significant following Bonferroni corrections(A1:p=0.177, A7:p=0.235). Conclusion : We couldn't find any association between schizophrenia and the synapsin III gene. Given the small number of subjects studied, further investigations are needed.

• Molecules and Cells
• /
• v.41 no.5
• /
• pp.413-422
• /
• 2018

Soybean transgenic plants with ectopically expressed AtABF3 were produced by Agrobacterium-mediated transformation and investigated the effects of AtABF3 expression on drought and salt tolerance. Stable Agrobacterium-mediated soybean transformation was carried based on the half-seed method (Paz et al. 2006). The integration of the transgene was confirmed from the genomic DNA of transformed soybean plants using PCR and the copy number of transgene was determined by Southern blotting using leaf samples from $T_2$ seedlings. In addition to genomic integration, the expression of the transgenes was analyzed by RT-PCR and most of the transgenic lines expressed the transgenes introduced. The chosen two transgenic lines (line #2 and #9) for further experiment showed the substantial drought stress tolerance by surviving even at the end of the 20-day of drought treatment. And the positive relationship between the levels of AtABF3 gene expression and drought-tolerance was confirmed by qRT-PCR and drought tolerance test. The stronger drought tolerance of transgenic lines seemed to be resulted from physiological changes. Transgenic lines #2 and #9 showed ion leakage at a significantly lower level (P < 0.01) than ${\underline{n}}on-{\underline{t}}ransgenic$ (NT) control. In addition, the chlorophyll contents of the leaves of transgenic lines were significantly higher (P < 0.01). The results indicated that their enhanced drought tolerance was due to the prevention of cell membrane damage and maintenance of chlorophyll content. Water loss by transpiration also slowly proceeded in transgenic plants. In microscopic observation, higher stomata closure was confirmed in transgenic lines. Especially, line #9 had 56% of completely closed stomata whereas only 16% were completely open. In subsequent salt tolerance test, the apparently enhanced salt tolerance of transgenic lines was measured in ion leakage rate and chlorophyll contents. Finally, the agronomic characteristics of ectopically expressed AtABF3 transgenic plants ($T_2$) compared to NT plants under regular watering (every 4 days) or low rate of watering condition (every 10 days) was investigated. When watered regularly, the plant height of drought-tolerant line (#9) was shorter than NT plants. However, under the drought condition, total seed weight of line #9 was significantly higher than in NT plants (P < 0.01). Moreover, the pods of NT plants showed severe withering, and most of the pods failed to set normal seeds. All the evidences in the study clearly suggested that overexpression of the AtABF3 gene conferred drought and salt tolerance in major crop soybean, especially under the growth condition of low watering.

• Nutrition Research and Practice
• /
• v.10 no.1
• /
• pp.115-124
• /
• 2016

BACKGROUND/OBJECTIVES: This is the first study to identify common genetic factors associated with the basal metabolic rate (BMR) and body mass index (BMI) in obese Korean women including overweight. This will be a basic study for future research of obese gene-BMR interaction. SUBJECTS/METHODS: The experimental design was 2 by 2 with variables of BMR and BMI. A genome-wide association study (GWAS) of single nucleotide polymorphisms (SNPs) was conducted in the overweight and obesity (BMI > $23kg/m^2$) compared to the normality, and in women with low BMR (< 1426.3 kcal/day) compared to high BMR. A total of 140 SNPs reached formal genome-wide statistical significance in this study (P < $1{\times}10^{-4}$). Surveys to estimate energy intake using 24-h recall method for three days and questionnaires for family history, a medical examination, and physical activities were conducted. RESULTS: We found that two NRG3 gene SNPs in the 10q23.1 chromosomal region were highly associated with BMR (rs10786764; $P=8.0{\times}10^{-7}$, rs1040675; $2.3{\times}10^{-6}$) and BMI (rs10786764; $P=2.5{\times}10^{-5}$, rs10786764; $6.57{\times}10^{-5}$). The other genes related to BMI (HSD52, TMA16, MARCH1, NRG1, NRXN3, and STK4) yielded P < $10{\times}10^{-4}$. Five new loci associated with BMR and BMI, including NRG3, OR8U8, BCL2L2-PABPN1, PABPN1, and SLC22A17 were identified in obese Korean women (P < $1{\times}10^{-4}$). In the questionnaire investigation, significant differences were found in the number of starvation periods per week, family history of stomach cancer, coffee intake, and trial of weight control in each group. CONCLUSION: We discovered several common BMR- and BMI-related genes using GWAS. Although most of these newly established loci were not previously associated with obesity, they may provide new insights into body weight regulation. Our findings of five common genes associated with BMR and BMI in Koreans will serve as a reference for replication and validation of future studies on the metabolic rate.

• Journal of Distribution Science
• /
• v.12 no.8
• /
• pp.113-121
• /
• 2014

Purpose - Recently, the number of corporations that practice environmental and social responsibility, besides engaging in traditional profit-seeking activities, has been growing steadily, as interest in Corporate Social Responsibility (CSR) is increasing. Recent research on CSR practices has identified the relationship between CSR activities and corporate value as one of the main issues in this respect. Considering that donations constitute a large proportion of a company's charitable activities, we considered the extent of donation expenses as a charitable activity in order to mitigate sample selection bias. Specifically, we analyzed the impact of donation expenses on firm value, while investigating if this impact varied in response to the level of corporate governance of firms. Research design, data, and methodology - We used non-financial firms listed on the Korean Stock Exchange, having their fiscal year end in December, and the sample period was 2006-2013. For the dependent variable, Tobin's q was used as the corporate value, and for the independent variable, donations were measured as the donation-expense-to-sales ratio. Corporate governance scores, as rated by the Korea Corporate Governance Service, were used to measure corporate governance levels because they consider the overall aspects of governance, including ownership structure, the board of directors, and the audit mechanism of individual companies. To examine the impact of donations on a company in relation to the level of corporate governance, we estimated regression models using the interaction terms of the governance dummy and donation variables. Then, we further estimated the regression models of two sub-samples that were classified according to the level of corporate governance. Similar to previous studies, the study uses variables that affect firm value, such as R&D expenditure, advertising expenses, EBITDA, debt-to-equity ratio, sales growth, company age, and company size as control variables. Results - The empirical results show that firm value significantly increased in response to an increase in donation expenses. Upon including the interaction terms of governance level dummy variables and donations, the coefficients of the interaction terms show significant positive values, while those of donation variables show significant negative values. In the strong governance sub-sample, the relationship between the donation expenses and corporate value was statistically positive (+) and significant. However, in the weak governance sub-sample, the relationship between the donation expenses and corporate value was statistically insignificant and negative (-). Conclusions - The empirical results suggest that donation expenses are significantly linked to an enhanced corporate value if firms have a good corporate governance structure. However, if the corporate governance structure is weak, the same relationship is not necessarily observed. The results of this study show that if a firm has high corporate governance, CSR practices enhance the company's reputation such that it has a positive (+) relationship with corporate value. If a firm has weak corporate governance, on the other hand, CSR practices are recognized as an agency cost and do not increase corporate value.

• Journal of Korea Port Economic Association
• /
• v.34 no.3
• /
• pp.93-112
• /
• 2018

The purpose of this study is to analyze the flow of e-commerce freight transported by maritime transportation for China and to identify the characteristics of cargo by region/item for finding the ways to promote e-commerce export to China. Thus, this study analyzed the e-commerce export and import data on cargo moved via maritime transportation between Korea and China from 2015 to 1Q18, using Origin-Destination(OD) analysis and visualization techniques. The results indicated that the largest number of Chinese e-commerce cargoes were imported at Incheon Port, which has a clearance facility for e-commerce cargo. In the case of Pyeongtaek Port, e-commerce cargo imported from China has transported to Incheon Customs again, causing the inefficiency through the customs clearance process. Unlike the case of e-commerce imports where the final destination is distributed nationwide, e-commerce products exported to China through maritime transportation were found to be mainly confined to Seoul and Gyeonggi provinces, where freight forwarding companies and forwarders are concentrated. In addition, unlike e-commerce import cargoes, e-commerce items exported through maritime transportation were mainly confined to clothing and cosmetics, and export volume was also less than imports. This study provides some possible strategies to increase the volume of freight and to attract export products as follows: i) to diversify products exported to China through e-commerce transshipment, ii) to diversify export items by building the cold chain in e-commerce transport with China.