• The korean journal of orthodontics
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• v.30 no.2 s.79
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• pp.175-183
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• 2000

The purpose of this study was to identify the compensatory adaptation of dentoalveolar structure according to the various skeletal relation through the statistical correlation between the anteroposterior, vertical skeletal and dentoalveolar relation. For this study, the sample were consisted of 101 adult subjects (51male and 50 female, mean age; male 23.6 years, female 21.5 years) who had good occlusion with the range of normal overjet and overbite and acceptable Angle's class I molar relationship which had not been related orthodontically The results were as follows : 1. Even though acceptable normal occlusion, the range of measurements which represent anteroposterior, vertical skeletal relation and dentoalveolar relation were very wide. 2. Upper and lower incisor axis were significantly correlated with anteroposterior skeletal relation, which means the mote lingual inclination of upper anterior teeth and the more labial inclination of lower anterior teeth according to the more anterior position of mandible to the maxilla (P<0.01). 3. Upper and 1ower anterior alveolar bone height was statistically correlated with the lower anterior vertical skeletal height. 4. Upper and 1ower alveolar bone height were not correlated with anteroposterior skeletal relation (P>0.05). 5. The correlation between the incisor axis and vertical skeletal was more closely related in upper anterior teeth than the lower anterior teeth. To summarize the above results, even though acceptable normal occlusion, skeletal and dentoalveolar relation was very widely ranged, and there were close relationship between the anteroposterior skeletal relation and the inclination of upper and lower anterior teeth and between the vertical skeletal relation and upper and lower anterior alveolar bone height. These finding can be concluded as compensatory adaptation to the different skeletal relationship.

• Economic and Environmental Geology
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• v.53 no.5
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• pp.619-629
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• 2020

The National Groundwater Monitoring Network (NGMN) in South Korea has been implemented in alluvial/ bedrock aquifers for efficient management of groundwater resources. In this study, aquifer types were reclassified with unconfined and confined aquifers based on water-level fluctuation and water quality characteristics. Principal component analysis (PCA) of water-level data from paired monitoring wells of alluvial/bedrock aquifers results in the principal components of both aquifers showing similar water-level fluctuation pattern. There was no significant difference in the rate of water-level rises responding to precipitations and in the NO₃-N concentrations between the alluvial and bedrock aquifers. In contrast, in the results classified with the hydrogeological type, the principal components of water level were different between unconfined and confined conditions. The water-level rises to precipitation events were estimated to be 4.6 (R²=0.8) in the unconfined and 2.1 (R²=0.4) in the confined aquifers, respectively, indicating less impact of precipitation recharge to the confined aquifer. The confined aquifers have the average NO₃-N concentration below 3 mg/L, implying the natural background level protected from the sources at surface. In summary, reclassification of aquifers into hydrogeological types clearly shows the differences between unconfined and confined aquifers in the water-level fluctuation pattern and NO₃-N concentrations. The hydrogeologic condition of aquifer could improve groundwater resource management by providing critical information on groundwater quantity through recharge estimation and quality for protection from potential contamination sources.

• Journal of Soil and Groundwater Environment
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• v.13 no.6
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• pp.72-84
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• 2008

This study was carried out to provide proper management plans for small portable water supply system in the Nonsan area through water quality monitoring, hydrogeochemical investigation and multivariate statistical analyses. Nonsan area is a typical rural area heavily depending on small water supply system for portable usage. Geology of the area is composed of granite dominantly along with metasedimentary rocks, gneiss and volcanic rocks. The monitoring results of small portable water supply system showed that 13-21% of groundwaters have exceeded the groundwater standard for drinking water, which is 5 to 8 times higher than the results from the whole country survey (2.5% in average). The major components exceeding the standard limits are nitrate-nitrogen, turbidity, total coliform, bacteria, fluoride and arsenic. High nitrate contamination observed at southern and northern parts of the study area seems to be caused by cultivation practices such as greenhouses. Although Ca and $HCO_3$ are dominant species in groundwater, concentrations of Na, Cl and $NO_3$ have increased at the granitic area indicating anthropogenic contamination. The groundwaters are divided into 2 groups, granite and metasedimentary rock/gneiss areas, with the second principal component presenting anthropogenic pollution by cultivation and residence from the principal components analysis. The discriminant analysis, with an error of 5.56% between initial classification and prediction on geology, can explain more clearly the geochemical characteristics of groundwaters by geology than the principal components analysis. Based on the obtained results, it is considered that the multivariate statistical analysis can be used as an effective method to analyze the integrated hydrogeochemical characteristics and to clearly discriminate variations of the groundwater quality. The research results of small potable water supply system in the study area showed that the groundwater chemistry is determined by the mixed influence of land use, soil properties, and topography which are controlled by geology. To properly control and manage small water supply systems for central and local governments, it is recommended to construct a total database system for groundwater environment including geology, land use, and topography.

• Economic and Environmental Geology
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• v.44 no.2
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• pp.135-152
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• 2011

Nitrate concentrations in springs at the southern slope of Jeju Island were predicted using multiple linear regression (MLR) of spatial variables including hydrogeological parameters and land use characteristics. Springs showed wide range of nitrate concentrations from <0.02 to 86 mg/L with a mean of 20 mg/L. Spatial variables were generated for the circular buffer when the optimal buffer radius was assigned as 400 m. Selected regression models were tested using the p values and Durbin-Watson statistics. Explanatory variables were selected using the adjusted $R^2$, Cp (total squared error) and AIC (Akaike's Information Criterion), and significance. In addition, mutual linear relations between variables were also considered. Small portion of springs, usually <10% of total samples, were identified as outliers indicating limitations of MLR using circular buffers. Adjusted $R^2$ of the proposed models was improved from 0.75 to 0.87 when outliers were eliminated. In particular, the areal proportion of natural area had the greatest influence on the nitrate concentrations in springs. Among anthropogenic land uses, the influence of nitrate contamination is diminishing in the following order of orchard, residential area, and dry farmland. It is apparent quality of springs in the study area is likely to be controlled by land uses instead of hydrogeological parameters. Most of all, it is worth highlighting that the contamination susceptibility of springs is highly sensitive to nearby land uses, in particular, orchard.

• Clinical and Experimental Pediatrics
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• v.49 no.6
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• pp.617-622
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• 2006

Purpose : High-Sensitivity C-reactive protein(hs-CRP) has been recognized as a very useful and sensitive predictor of the future risk of myocardial infarction. But the clinical significance of hs-CRP in children remains uncertain. To confirm the existence of obesity-induced vascular inflammation and the association between metabolic syndromes and elevation of CRP in children, we investigated the relationship among CRP, obesity, blood pressure(BP), and serum lipids in schoolboys. Methods : Twenty-eight obese(BMI $29.61{\pm}3.29kg/m^2$) and 93 non-obese(BMI $18.99{\pm}2.21kg/m^2$) boys aged 14 years were examined. Serum CRP levels was measured by the high sensitive latex turbidimetric immunoassay and subjects with CRP levels below 0.3 mg/dL were adopted to avoid the influence of acute infection. Results : Obese children had significantly higher hs-CRP levels than their non-obese group($0.104{\pm}0.075$ vs. $0.054{\pm}0.005mg/dL$). In the obese group, BMI, systolic blood pressure, diastolic blood pressure, apolipoprotein B, atherogenic index, and triglyceride were significantly higher than in nonobese. The BMI, diastolic blood pressure, apolipoprotein E, atherognic index, and triglyceride showed positive correlation with log CRP by simple regression. Multiple regression analysis indicated that BMI and apolipoprotein E were strongly related to CRP. Conclusion : This study revealed that obese children tended to have higher levels of serum hsCRP, BP elevation and dyslipidemia than the control group and that BMI and apolipoprotein E were strongly related to CRP. These results indicate that obesity related metabolic syndrome can be developed in children.

• Clinical and Experimental Pediatrics
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• v.49 no.6
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• pp.643-647
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• 2006

Purpose : Recently, incidences of chronic cough with allergic disease have been increased. The identification of specific allergens for chronically coughing children is significant for diagnosis, proper treatment and prevention. The aim of this study was to identify significant contributors for sensitization in chronically coughing children. Methods : A total of 106 children, aged 1-6 years, visiting for chronic cough(>3 weeks), were tested for inhalant multiple allergosorbent assay(MAST), eosinophil count and total IgE. Parents completed a questionnaire on past history of atopy(infantile eczema) and bronchiolitis, family history of allergy, breastfeeding, smoking, pets and floor coverings at home. Results : Significant contributors for sensitization were : age(4-6 years), infantile eczema, positive family history of allergy and smoking by family. Conclusion : We were able to identify significant contributors for sensitization in chronically coughing children.

• Clinical and Experimental Pediatrics
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• v.52 no.6
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• pp.655-660
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• 2009

Purpose : To compare birth weight between infants with a single umbilical artery (SUA) and normal infants, investigate the associated anomalies of infants with SUA and isolated SUA (no abnormality of external appearance on birth, except SUA), and determine the prognosis of infants with isolated SUA. Methods : Live-born infants with SUA (n=59) detected by physical examination from among 15,193 live births in seven university hospitals in Korea between January 1, 2004, to August 1, 2007, were reviewed retrospectively, with 236 normal infants serving as the control group. Results : A statistical difference was observed between the groups in birth weight and in vitro fertilization. The incidence of infants with SUA was 0.37%. Congenital malformations were observed in 21 infants with cardiovascular (n=15, 25.4%), gastrointestinal (n=2, 3.4%), genitourinary (n=9, 15.3%), neuromusculoskeletal (n=6, 10.2%), central nervous system (n=1, 1.7%), chromosomal (n=1, 1.7%), and other (n=3, 5.1%) abnormalities. There were 49 (83.1%) infants with isolated SUA in this study population; among them, the associated congenital malformations were cardiovascular (n=6, 12.2%) and genitourinary (n=6, 12.2%) abnormalities. Two infants with cyanotic heart disease were operated and four infants with acyanotic heart disease showed improvements without any treatment. Six infants with genitourinary abnormalities on renal ultrasound had mild hydronephrosis without further consequences. Conclusion : The incidence of structural abnormalities in the cardiovascular and genitourinary systems is high and the genitourinary anomalies associated with isolated SUA have relatively good prognosis.

• Journal of radiological science and technology
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• v.36 no.3
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• pp.209-217
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• 2013

Adiponectin (AdipoN), brain-derived nerotrophic factor (BDNF) and leptin (LeP) are mainly secreted from adipose tissue and are known to be involved in regulation of the development of obese. However, there are not many studies on the association between abdominal fat and neuropeptides such as AdipoN, BDNF and LeP. The aim of this study was undertaken to investigate the association between abdominal fat thickness, neuropeptides and cardiovascular disease (CVD) risk factors. The participants in the study were 138 male employees without CVD. This study was approved by the Institutional Review Board of Occupational Safety and Health Research Institute. Written informed consent for the participants in this study was obtained from all individuals. We obtained subcutaneous fat thickness (SFT) and visceral fat thickness (VFT) by using ultrasonography and neuropeptides levels were measured with ELISA kit according to the method suggested by kit manufacturer. The mean SFT and VFT were $1.58{\pm}0.51$ and $4.52{\pm}1.44$ cm. The mean concentrations of AdipoN, BDNF and LeP were $3.14{\pm}3.52$ ng/ml, $24.11{\pm}8.52$ pg/ml and $4.27{\pm}2.38$ ng/ml, respectively. VFT were positively correlated with total cholesterol (r=0.217, p<0.05), LDL-cholesterol (r=0.271, p<0.01), triglyceride (r=0.233, p<0.05) and insulin (r=0.338, p<0.01), but was inversely correlated with HDL-cholesterol (r=-420, p<0.01). AdipoN levels were positively correlated with HDL-cholesterol (r=0.220, p<0.05) and were inversely correlated with total cholesterol (r=-0.196, p<0.05), LDL-cholesterol (r=-0.190, p<0.05), triglyceride (r=-0.199, p<0.05), SFT (r=-0.195, p<0.05) and VFT (r=-0.412, p<0.01). However, LeP levels showed a reverse trend to AdipoN. AdipoN level was significantly higher in non-obese participants (BMI<25 kg/m), but LeP concentration was significantly higher in obese participants (BMI>25 kg/m) than in non-obese. On multiple logistic regression analysis, obese were significantly associated with AdipoN (odds ratio=0.784) and LeP (odds ratio=1.494). These results suggested that AdipoN and LeP concentrations are affected abdominal fat and that dysfunction and/or declination in the production and secretion of neuropeptides might induced ultimately obese and CVD.

• Journal of Soil and Groundwater Environment
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• v.13 no.5
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• pp.57-73
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• 2008

Nitrate concentrations were measured up to 49 mg/L (as $NO_3$-N) and 22% of the samples exceeded drinking water standard in shallow and bedrock groundwater of the northern Nonsan area. Nitrate concentrations showed a significant difference among land use groups. To predict nitrate concentration in groundwater, multiple regression analysis was carried out using hydrogeologic parameters of soil media, topography and land use which were categorized as several groups, well depth and altitude, and field parameters of temperature, pH, DO and EC. Hydrogeologic parameters were quantified as area proportions of each category within circular buffers centering at wells. Regression was performed to all the combination of variables and the most relevant model was selected based on adjusted coefficient of determination (Adj. $R^2$). Regression using hydrogelogic parameters with varying buffer radii show highest Adj. $R^2$ at 50m and 300m for shallow and bedrock groundwater, respectively. Shallow groundwater has higher Adj. $R^2$ than bedrock groundwater indicating higher susceptibility to hydrogeologic properties of surface environment near the well. Land use and soil media was major explanatory variables for shallow and bedrock groundwater, respectively and residential area was a major variable in both shallow and bedrock groundwater. Regression involving hydrogeologic parameters and field parameters showed that EC, paddy and pH were major variables in shallow groundwater whereas DO, EC and natural area were in bedrock groundwater. Field parameters have much higher explanatory power over the hydrogeologic parameters suggesting field parameters which are routinely measured can provide important information on each well in assessment of nitrate contamination. The most relevant buffer radii can be applied to estimation of travel time of contaminants in surface environment to wells.

• Radiation Oncology Journal
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• v.8 no.2
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• pp.207-212
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• 1990

To determine the correlation between the response to induction chemotherapy and subsequent radiotherapy we analyzed the clinical records of 60 patients with locally advanced carcinoma of the head and neck retrospectively who had completed a full course ($2\~3$ cycle) of induction chemotherapy and curative radiotherapy in Korea Cancer Center Hospital between 1986 and 1989. Chemotherapy was administeredd with CDDP+Bleomycin (BP) in 20, CDDP+5-FU (FP) in 37, and hybrid of BP and FP in three patients. Radiotherapy was giver conventionally with a dose of 65 to 75 Gy or more over seven to eight weeks according to the size of lesion. Response rates following induction chemotherapy were $80\%$ for the tumors and $879\%$ for the nodes whereas complete reponse rates were $12\%\;and\;13\%$, respectively. Six months after radiotherapy $67\%$ of the tumors and $77\%$ of the nodes achieved a complete response. Among the 48 tumor responders and the 31 nodal responders to chemotherapy,39 ($81\%$) and 28 ($90\%$), respectively, achieved complete response after radiotherapy. Thus, whether or not the tumor and node respond to induction chemotherapy was predictive of the response to subsequent radiotherapy (p<0.0005 in tumor, p<0.0001 in node). By reanalyzing according to disease subsets (i.e. primary site, T-stage, N-stage) this relationship was not observed at T1-T2 disease (p>0.3). Therefore the tumor or node's response to induction chemotherapy is a predictor for subsequent radiotherapy except in T1-T2 tumors, and complete response to radiotherapy can be expected despite the failure of induction chemotherapy in $T_1-T_2$ tumors.