• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.2
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• pp.159-167
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• 2010

The purpose of this study was to identify patterns of caries in the dentition of preschool children using cluster analysis and multidimensional scaling. 815 preschool children aged 36-71 months old were examined for caries experience. The first four clusters in the cluster analysis were (1) molars, (2) upper incisors, (3) lower 1st molars, and (4) upper 1st molars in teeth, (1) occlusal surfaces of lower molars and upper 2nd molars, (2) mesial surfaces of upper central incisors, (3) occlusal surfaces of lower 1st molars, and (4) separation between occlusal surfaces of upper and lower 2nd molars in tooth surfaces, and (1) proximal surfaces of upper anterior teeth, (2) occlusal surfaces of lower molars, (3) buccolingual surfaces of upper anterior teeth and (4) buccolingual, proximal, and occlusal surfaces of upper molars and buccolingual and proximal surfaces of lower molars in tooth surfaces groups. In the multidimensional scaling analysis, teeth could be divided into lower 1st molars, upper 1st molars, upper central incisors, upper lateral incisors, lower 2nd molars, upper 2nd molars, and the rest(canines, lower incisors), tooth surfaces could be divided into occlusal surfaces of lower molars, mesial surfaces of upper central incisors, occlusal surfaces of upper molars, and the rest, and tooth surface groups could be divided into proximal surfaces of upper anterior teeth, buccolingual surfaces of upper anteiror teeth, occlusal surfaces of lower molars, and the rest in the order of the distance from others. In the cluster analysis and the multidimensional scaling analysis, caries patterns were different according to the age.

• Journal of Environmental Health Sciences
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• v.42 no.3
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• pp.147-159
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• 2016

In South Korea, many cases of humidifier disinfectant-associated lung injury (HDLI) have been reported among people who used humidifier products containing humidifier disinfectant (HD). The objective of this study is to characterize exposure to HD among a total of 221 HDLI patients who used HD. Information and data on the HDs used were collected through a structured questionnaire and home environmental investigations. The conditions of these 221 HDLI patients were clinically confirmed to be caused by the use of HD. Children aged under 5 years old made up the highest proportion of HDLI cases (n=125, 56.6 %), followed by pregnant women (n=35, 15.8%). Forty-three percent (n=95) of the victims died. There were three cases of fetuses and 35 pregnant women among the victims. The number of HDLI patients who used only the Oxy Saksak brand of HD was found to be 85 (38.5%), followed by the HD brands Cefu (n=24, 10.9%), Lottemart Wiselect (n=9, 4.1%) and Aekyung (n=3). Patients who exclusively used HD brands containing polyhexamethylene guanidine phosphate (PHMG) (n=13, 55.7%) as an active ingredient made up the largest share, followed by those who exclusively used HD containing only oligo(2-(2-ethoxy) ethoxyethyl guanidinium (PGH) (n=24, 10.9%) and by those who only used a mixture of chloromethylisothiazolinone (CMIT) and methylisothiazolinone (MIT) (n=3, 1.4%). HD products containing PHMG were found to be the most commonly used among the confirmed HDLI patients. Three exposed fetuses who never used HD after birth developed lung injuries, indicating a probability of exposure to HD during gestation. All HDLI patients responded that they used HD while sleeping and for longer than 10 hours per day. In conclusion, the development of HDLI was clinically found to be associated with the use of several HD products containing PHMG, PGH and CMIT/MIT.

• Clinical and Experimental Pediatrics
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• v.48 no.11
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• pp.1219-1224
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• 2005

Purpose : The prevalence of obesity in children and adolescents has been rising rapidly in Korea because of changes of diet and lifestyle. As with adults, obesity in children and adolescents can cause diabetes mellitus, hyperlipidemia, cardiovascular diseases and renal diseases. The aim of the present study is to examine the relation of obesity, glomerular filtration rate(GFR) and serum cystatin C concentration in children and adolescents. Methods : Data of 115 children and adolescents aged between 6 years and 20 years without clinical evidence of renal diseases were included in the study. From May 2004 to December 2004, blood samples were collected from children and adolescents who were seen at the Department of Pediatrics at Chungang University Yongsan Hospital. Obesity degrees and body mass indices(BMI) were measured, and GFRs were estimated from Schwartz's formula. Serum cystatin C was measured by particle enhanced nephelometric immunoassay using Behring Nephelometer II. Results : GFRs were significantly different between the obese group(BMI >95 percentile, $145.79{\pm}23.10mL/min$) and the non-obese group(BMI <95 percentile, $134.61{\pm}26.19mL/min$) divided by BMI (P=0.031). GFRs were not significantly different between the obese group(obesity degree >120 percent, $144.29{\pm}23.08mL/min$) and the non-obese group(obesity degree <120 percent, $134.54{\pm}26.57mL/min$) divided by obesity degree(P=0.051), but were significantly different between severe obese group (obesity degree >150 percent, $155.55{\pm}20.40mL/min$) and the non-obese group(P=0.004). GFRs were correlated positively with BMI($r^2=0.037$, P=0.039), but were not correlated significantly with obesity degree($r^2=0.030$, P=0.066). Serum cystatin C concentrations were not significantly different between the obese group and the non-obese group, divided by BMI as well as by obesity degree(P>0.05). Conclusion : Obesity may lead to an alteration of renal hemodynamics such as hyperfiltration, appropriate control and management for obesity is necessary.

• Clinical and Experimental Pediatrics
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• v.46 no.4
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• pp.351-357
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• 2003

Purpose : To raise awareness of the clinical importance of, and the need for proper management of acute focal bacterial nephritis(AFBN), we analyzed 22 AFBN patients and 22 other upper urinary tract infection patients by use of comparative studies. Methods : From January 2000 to May 2002, 22 AFBN patients aged from 1 month to 12 months were selected. As a control group, 22 UTI patients with no radiologic abnormalities were selected and matched by age and sex. Results : The incidence of AFBN was more common in boys than in girls. Since both groups had similar symptoms, it was difficult to diagnose AFBN by clinical presentations alone. ESR and CRP were significantly higher in AFBN patients. The most common causative organism was E. coli in both groups. On the sonographic findings, the most lesions were seen on the upper lobe of the kidney; more frequently, on left kidney. The lesions showed globular or wedge-shaped increased echogenecity. $^{99m}Tc-DMSA$ scan showed the complete coincidence of the location, size and shape in all cases compared to the findings of renal sonography. Conclusion : The roles of renal sonography and DMSA scan were very important, and ultrasonography was an excellent initial tool in diagnosing AFBN. Since the degree of infection in AFBN is more severe than other urinary tract infections and evollution into a renal abscess is possible, early diagnosis and appropriate antibiotics therapy is essential.

• Clinical and Experimental Pediatrics
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• v.52 no.2
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• pp.159-166
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• 2009

Purpose : Iron deficiency anemia (IDA) is one of the most common nutritional deficiencies in children on a weaning diet. We investigated weaning practices in infants and children, as well as their mothers' knowledge about weaning. Methods : We investigated 129 children with IDA and 166 without IDA (aged 6-36 months) who had visited 10 university hospitals between March 2006 and July 2007. We investigated the hematologic values of both groups. A questionnaire on weaning was answered by the mothers of these children. Results : The hematologic values in the IDA group showed a significant difference from those in the comparison group (P<0.05). Children who were solely breastfed until 6 months of age were 85%, 34% (P<0.05), and weaning was started by 6.3, 6.4 months, respectively (P>0.05). Rice gruel, boiled rice, and fruit juice accounted for approximately 80% of the starting foods in both groups (P>0.05). Only 40% of the children in the IDA group had a balanced diet within a month, versus 38% in the comparison group. In response to questions about the necessity of iron-fortified foods for breast-fed infants, less than 50% of mothers in both groups answered correctly. In the IDA group, 42% showed serum ferritin less than 10 ng/mL, while 92% showed serum MCV less than 72 fL. Conclusion : In conclusion, collection of information on history should be thorough for feeding and selective examinations for IDA in high-risk groups. Considering the adaptation period, we suggest beginning children on a weaning diet at 45 months. In addition, we need to educate mothers on weaning practice, especially on the necessity of iron-fortified foods for breast-fed infants.

• Journal of Nutrition and Health
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• v.53 no.5
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• pp.518-531
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• 2020

Purpose: This study examined the association between fruit and vegetable intake and mental health in Korean adolescents. Methods: This study used the data from the 2014-2017 Korea Youth Risk Behavior Survey, a national cross-sectional survey on 137,101 boys and 130,806 girls aged 12-18. Fruit and vegetable intake was assessed based on the frequency of consumption. The outcome variables were the perceived happiness, perceived stress, depressive symptom and suicidal ideation over the previous 12 months. Logistic regression models were used after adjusting for the demographic, life style and other dietary factors. Results: Only 34% and 29% of Korean adolescents consumed fruits more than 5 times/week and vegetables more than 2 times/day, respectively; whereas 37%, 25% and 12.2% of Korean adolescents had perceived stress, depressive symptom and suicidal ideation, respectively. After adjusting for the confounding variables, the greater consumption of fruit and vegetable were all associated with a higher odds of perceived happiness; the adjusted odds ratios (AORs) (95% CI) were 1.53 (1.46-1.60) in boys and 1.82 (1.73-1.90) in girls who consumed fruit ≥ 5 times/week, and 1.65 (1.54-1.76) in boys and 1.62 (1.51-1.72) in girls who consumed vegetable ≥ 2 times/day. In contrast, the consumption of fruit or vegetable were all significantly associated with a lower odds of perceived stress, depressive symptom, and suicidal ideation; the AOR (95% CI) were 0.70 (0.67-0.73), 0.88 (0.84-0.93), and 0.78 (0.73-0.83) in boys who consumed fruit 3-4 times/week, and 0.71 (0.67-0.76), 0.88 (0.81-0.94), and 0.68 (0.62-0.74) in boys who consumed vegetable 5-7 times/week. Similar associations of fruit or vegetable consumption with perceived stress, depressive symptom, or suicidal ideation were found in girls. Conclusion: These findings provide evidence that increasing fruit and vegetable intake is important for better mental health among adolescents.

• Journal of Nutrition and Health
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• v.50 no.6
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• pp.565-577
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• 2017

Purpose: There have been limited studies investigating the relationship between high-sensitivity C-reactive protein (hsCRP), metabolic diseases, and dietary factors in Korean adults. Here, we examined the association between nutrient intake and serum hsCRP among Korean adults. Methods: Using data on 2,624 healthy Korean adults (1,537 women and 1,087 men) from the 2015 Korea National Health and Nutrition Examination Survey, demographic, anthropometric, biochemical, and dietary factors were analyzed once the subjects were grouped into either sex, age, or BMI. Nutrient intake was evaluated using the dietary data obtained by one-day 24-hour recall. Based on the guidelines of the US Centers for Disease Control and Prevention and the American Heart Association, hsCRP level was classified as HCRPG (High CRP Group, hsCRP > 1 mg/L) and LCRPG (Low CRP Group, hsCRP ${\leq}1mg/L$). Proc surveyreg procedure was performed to examine the associations between nutrient intake and hsCRP after adjustment for potential confounding variables. Results: The average hsCRP level of healthy Korean adults was $0.95{\pm}0.03mg/L$ ($0.97{\pm}0.04mg/L$ in men, $0.92{\pm}0.05mg/L$ in women). Obese subjects had significantly higher hsCRP than non-obese subjects in both sexes. The hsCRP level was positively associated with current smoking, physical inactivity, BMI, waist circumference, fasting blood glucose, triglycerides, total cholesterol, LDL-cholesterol, and blood pressure and inversely associated with HDL-cholesterol. LCRPG had significantly higher intake of dietary fiber compared to HCRPG in women. High hsCRP level was associated with more dietary cholesterol intake but less omega-3 fatty acid intake among subjects aged ${\geq}50y$. HCRPG of obese subjects had higher intakes of fat and saturated fatty acid than LCRPG. Conclusion: The hsCRP level is closely associated with several lifestyle variables and nutrient intake in healthy Korean adults. Individuals with high hsCRP level show low intakes of dietary fiber and omega-3 fatty acids but high intakes of dietary fat and cholesterol. Our findings suggest that a potential anti-inflammatory role for nutrients and lifestyle in the Korean adult population.

• Korean Journal of Agricultural Science
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• v.18 no.2
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• pp.104-113
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• 1991

This experiment was conducted to find the effect of calcium salts on the inhibition of 'Campbell Early' grape(Vitis labruscana B.) berry absicission induced by ethephon. Ethylene evolution, berry abscission rate, and fruit quality were examined. Several mineral contents were determinded in the berries and morphological changes of cells in abscission zone were also studied. 1. Calcium acetate($4.4-8.8g/{\ell}$) and calcium hydroxide($2.2-8.8g/{\ell}$) completely inhibited berry abscission when applied with ethephon 1,000 ppm while calcium chloride was less effective. 2. Ethylene evolution in the berries treated with ethephon alone reached to maximum peak one day after application. However, that peak in the treatment of ethephon with calcium acetate occurred 3 hours after application. 3. No decrease of ethylene production capacity was observed in the ethephon solution even when held up to 36 hours after preparation but the effect on berry abscission was significantly reduced. In contrast, ethylene production of the solution prepared with calcium acetate was greatly decreased along with the increase of holding time. The effect of calcium acetate in aged solution on the inhibition of berry abscission was not altered. 4. There were no differences in mineral contents such as Ca, Mg, and K between the berries sprayed with ethephon 500 ppm or not. Additional calcium accumulation was not found in the skin, flesh, and petiole of clusters sprayed with 3 kinds of calcium salts (1.5 g net Ca per liter) respectively when analyzed 2 weeks before maturity. 5. Ethephon (1,000 ppm) alone induced the development of abscission layer in petiole but those applied with calcium acetate (0.05 M) did not develop any distinct abscission layer 3days after treatment.

• Journal of Technologic Dentistry
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• v.20 no.1
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• pp.37-49
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• 1998

The specimens used were Ag-25 Pd-15 Cu ternary alloy and Au addition alloy. These alloys were melted and casted by induction electric furnace and centrifugal casting machine in Ar atmosphere. These specimens were solution treated for 2hr at $800^{\circ}C$ and were then quenched into iced water, and aged at $350{\sim}550^{\circ}C$ Age- hardening characteristics of the small Au-containing Ag-Pd-Cu dental alloys were investigated by means of hardness testing. X-ray diffraction and electron microscope observations, electrical resistance, ergy dispersed spectra and electron probe microanalysis. Principal results are as follows : Hardening occured in two stages, i.e., stage I in low temperature and stage II in high temperature regions, during continuous aging. The case of hardening in stage I was due to the formation of the $L1_0$ type face-centered tetragonal PdCu-ordered phase in the grain interior and hardening in stage I was affected by the Cu concentration. In stage II, decomposition of the ${\alpha}$ solid solution to a PdCu ordered phase($L1_0$ type) and an Ag-rich ${\alpha}2$ phase occurred and a discontinuous precipitation occurred at the grain boundary. From the electron microscope study, it was conclued that the cause of age-hardening in this alloy is the precipitation of the PdCu ordered phase, which has AuCu I type face-centered tetragonal structure. Precipetation procedure was ${\alpha}{\to}{\alpha}+{\alpha}_2+PdCu {\to}{\alpha}_1+{\alpha}_2+PdCu$ at Pd/Cu = 1.7 Ag-Pd-Cu alloy is more effective dental alloy as ageing treatment and is suitable to isothermal ageing at $450^{\circ}C$.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.2
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• pp.137-148
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• 1999

Purpose of the present study was to find the optimal ovulation induction medicine for the maturation and development of immature oocytes and culture media for 2-cell embryos in the mouse model. ICR female mouse aged 6 to 8 weeks, were stimulated with 5 IU PMSG injection. At 47 to 50 hour post-PMSG injection, ovaries were dissected out and oocytes-cumulus complexes were punctured. The oocyte-cumulus complexes were cultured in media containing various ovulation induction medicine, CC, HMG and Metrodin for 18 hours. Female ICR mice were stimulated with 5 IU PMSG and 48 hours later were injected 5 IU of hCG, then female and male mice were mated. At 48 hour post-hCG injection, oviducts were dissected out and 2-cell embryos were flushed. The 2-cell embryos were cultured in various media, Ham's F-10 media of milli-Q water $(3^{\circ})$, Ham's F-10 media of HPLC (high performance liquid chromatography, Baxter) water, Medicult media, HTF (human tubal fluid) media for 96 hours. The results were as follows. 1. When the oocytes-cumulus complexes were cultured in $10^{-9}{\mu}g/ml{\sim}10^{-8}{\mu}g/ml$ of CC, those were suppressed in meiotic maturation $(28.2{\sim}33.7%)$. Whereas the oocytes-cumulus complexes were cultured in $10^{-7}{\mu}g/ml{\sim}10^{-4}{\mu}g/ml$, these were not effected in meiotic maturation $(54.5{\sim}72.7%)$. 2. When the oocytes-cumulus complexes were cultured in $10^{-4}{\mu}g/ml{\sim}10^{-1}{\mu}g/ml$ of Metrodin, those were suppressed in meiotic maturation $(35.7{\sim}41.5%)$. Meanwhile the oocytes-cumulus complexes were cultured in $10^{-7}{\mu}g/ml{\sim}10^{-5}{\mu}g/ml$, those were not effected in meiotic maturation $(54.2{\sim}70.3%)$. 3. When the oocytes-cumulus complexes were cultured in $10^{-5}{\mu}g/ml{\sim}10^{-4}{\mu}g/ml$ of HMG, those were suppressed in meiotic maturation $(48.2{\sim}50.4%)$. As being cultured in $10^{-7}{\mu}g/ml{\sim}10^{-6}{\mu}g/ml$, increased in meiotic maturation $(75.8{\sim}80.7%)$. 4. When the 2-cell embryos were cultured in Ham's F-10 media of milli-Q water $(3^{\circ})$, Ham's F-10 media of HPLC (high performance liquid chromatograpy, Baxter) water, Medicult media, HTF (human tubal fluid) media, developmental rates to blastocyst and hatching for 96 hour were 50.0%, 45.2%, 71.5% and 95.6%, respectively.