• Korean Journal of Environmental Agriculture
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• v.37 no.4
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• pp.283-290
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• 2018

BACKGROUND: Pesticide residue analysis is an essential activity in order to establish the food safety of agricultural products. Analytical approaches to the food safety are required to meet internationally the guideline of Codex (Codex Alimentarius Commission, CAC/GL 40). In this study, we developed a liquid chromatograph-tandem mass spectrometer (LC-MS/MS) method to determine the herbicide clopyralid in food matrixes. METHODS AND RESULTS: Clopyralid was extracted with aqueous acetonitrile containing formic acid and the extracts were mixed in a citrate buffer consisted of magnesium sulfate anhydrous, NaCl, sodium citrate dihydrate and disodium hydrogencitrate sesquihydrate followed by centrifugation. The supernatants were filtered through a nylon membrane filter and used for the analysis of clopyralid. The method was validated by accuracy and precision experiments on the samples fortified at 3 different levels of clopyralid. LC-MS/MS in positive mode was employed to quantitatively determine clopyralid in the food samples. Matrix-matched calibration curves were inearranged from 0.001 to 0.25 mg/kg with r2 > 0.994. The limits of detection and quantification were determined to be 0.001 and 0.01 mg/kg, respectively. There covery values of clopyralid for tified at 0.01 mg/kg in the control samples ranged from approximately 82 to 106% with relative standard deviations below 2 0%. CONCLUSION: The method developed in this study meets successfully the Codex guideline for pesticide residue analysis in food samples. This, the method could be applicable to determine pesticides in foods produced domestically and internationally.

• Korean Journal of Psychosomatic Medicine
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• v.28 no.2
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• pp.116-125
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• 2020

Objectives : Self-poisoning is the leading cause of visits to the emergency departments after a suicide attempts. This study is aimed to compare the patient characteristics according to the category of drugs ingested by the patients who attempted suicide. Methods : All medical charts were retrospectively reviewed from patients who visited the emergency center, at Seoul Medical Center, due to intentional self-poisoning from April of 2011 to July of 2019. We investigated the information regarding the subtype and quantity of the intoxication drug, how it was obtained, suicidal history, and psychiatric history, as well as, sociodemographic information. Variables were compared between prescription drug (PD) and non-prescription drug (NPD) poisoning groups. Results : The mean age of the NPD poisoning group was significantly lower than that of the PD poisoning group. The patient ratio of those enrolled in national health insurance and living with spouses were significantly higher in the NPD poisoning group. Compared to the NPD poisoning group, the PD poisoning group had a higher incidence of mental illnesses, underlying diseases and ratio of involuntary visit to the emergency department. Among the prescription drugs, the benzodiazepine poisoning group had a higher rate of self-prescription than the non-poisoning group, while the zolpidem poisoning group had a higher rate of the using someone else's prescription than other drugs. Each single drug poisoning group (benzodiazepine, zolpidem, and antidepressant single-agent) had a higher rate of no mental illness than each of the mixed-poisoning group. Conclusions : Guidelines for regulating non-prescription drugs are needed as a matter of suicide prevention. Also, this study suggests that clinicians need to be careful when issuing prescriptions and should suicidal risk according to patients' characteristics, duration of follow-up and type of drug packaging.

• Journal of Food Hygiene and Safety
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• v.38 no.4
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• pp.211-216
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• 2023

A total of 100 commercially available olive oil products were analyzed for 179 pesticide residues using gas chromatography-tandem mass spectrometry (GC/MS/MS). The olive oil samples were mixed with organic solvents, centrifuged and frozen to remove fat, and pesticide residues were analyzed using the "quick, easy, cheap, effective, rugged, and safe" (QuEChERS) method. The determination coefficient (R²) of the analysis method used in this study was ≥0.998. The detection limit of the method ranged 0.004-0.006 mg/kg and its quantitative limit ranged 0.012-0.017 mg/kg. The recovery rate (n=5) measured at the level ranging 0.01-0.02, 0.1, and 0.5 mg/kg ranged 66.8-119.5%. The relative standard deviation (RSD) was determined to be ≤5.7%, confirming that this method was suitable for the "Guidelines for Standard Procedures for Preparing Food Test Methods". The results showed that a total of 151 pesticides (including difenoconazole, deltamethrin, oxyfluorfen, kresoxim-methyl, phosmet, pyrimethanil, tebuconazole, and trifloxystrobin) were detected in 64 of the 100 olive oil products. The detection range of these pesticide residues was 0.01-0.30 mg/kg. The percentage acceptable daily intake (%ADI) of the pesticides calculated using ADI and estimated daily intake (EDI) was 0.0001-0.1346, indicating that the detected pesticides were present at safe levels. This study provides basic data for securing the safety of olive oil products by monitoring pesticide residues in commercially available oilve oil products. Collectively, the analysis method used in this study can be used as a method to analyze residual pesticides in edible oils.

• Korean Journal of Cognitive Science
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• v.35 no.2
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• pp.129-159
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• 2024

In the process of reading, readers can process information not only within the fixated region, known as the fovea, but also in the parafoveal region to the right of the fovea. While the parafoveal semantic preview effect has been confirmed in eye-tracking experiments using boundary techniques, research on how the parafoveal preview effects differ depending on the degree of semantic relatedness is still limited. This study investigates the parafoveal preview effects as a function of semantic relatedness with the target word. The experiment utilized Korean-Chinese bilinguals and presented mixed-language sentences as experimental stimuli. Four parafoveal preview conditions were applied to the target words in each sentence: (1) Korean identical condition, where the parafoveal word was the same as the target word (e.g., "나라," meaning "country" in English), (2) Chinese synonymous condition, where the parafoveal word had the same meaning as the target word (e.g., "国家," also meaning "country" in English), (3) Chinese semantically related condition, where the parafoveal word was semantically related to the target word (e.g., "政权," meaning "political power" in English), and (4) Chinese unrelated condition, where the parafoveal word was semantically unrelated to the target word (e.g., "围裙," meaning "apron" in English). The study explored the parafoveal preview effect in terms of the degree of semantic association with the target word. We found the most pronounced preview effect in conditions where the preview and the target word shared the same meaning, and we also observed preview effects in conditions where the semantic relatedness with the target word was relatively weak. This study suggests that the degree of semantic relatedness between the parafoveal preview word and the target word can influence readers' reading processes. It contributes to a better understanding of readers' eye movements and comprehension processes, with potential implications for the development of effective reading strategies and educational methods.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.203-207
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• 2010

Purpose: Hepatitis B is infection caused by Hepatitis B virus (HBV). Currently, there are several methods, Kits and equipments for conducting Hepatitis B test. Due to ununiformed methods, it would cause some differences. To manage these differences, it needs process evaluating function of test system and reagent using particular standard substance. The aim of this study is to investigate tendency of RIA method's reagent used in Asan Medical Center through comparing several other test reagents using national standard substance. Materials and Methods: The standard substance in National Institute of Food and Drug Safety Evaluation's biology medicine consists of 5 things, 4 antigens and 1 antibody. We tested reagents using A, B company's Kits according to each test method. All tests are measured repeatedly to obtain accurate results. Results: Test result of "HBs Ag Mixed titer Performance panel" is obtained match rate compared S/CO unit standard with RIA method and EIA 3 reagents, CIA 2 reagents is that company A's reagent is 94.4% (17/18), 83.3% (15/18), B is 88.9% (16/18), 77.8% (14/18). Test result of "HBs Ag Low titer Performance panel" is obtain that EIA 2 reagents is shown 7 posive results, CIA 3 reagents is 11, and RIA method's company A's reagent is 3, B is 2 of 13 in low panel. "HBV surface antigen 86.76 IU/vial" tested dilution. A is obtain positive results to 600 times(0.14 IU/mL), B is 300 times (0.29 IU/mL). Case of "HBV human immunoglobulin 95.45 IU/vial", A is shown positive result to 10,000 times (9.5 mIU/mL) and B is 4,000 times (24 mIU/mL). Test result of "HBs Ag Working Standards 0.02~11.52 IU/mL" is shown that Company A's kit concentration level was 0.38IU/mL, company B was 2.23 IU/mL and higher level of concentration was positive results. Conclusion: When comparing various test reagents and RIA method according to National Standard substances for Hepatitis B test, we recognized that there were no significant trends between reagents. For hepatitis B virus antigen-antibody titers even in parts of the test up to 600 times the antigen, antibodies to 10,000 times the maximum positive results could be obtained. Therefore, we confirmed that results from Asan Medical Center are performed smoothly by reagents and system for hepatitis B virus test.

• Clinical and Experimental Pediatrics
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• v.51 no.1
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• pp.33-41
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• 2008

Purpose : It is now understood that blood pressure (BP) measurement in the routine pediatric examination is very important because of the relevance of childhood BP to pediatric health care and the development of adult essential hypertension. There hasn't been a reference table of BP for Korean children and adolescents up to now. This study was to make normative BP references and to provide criteria of hypertension for Korean children and adolescents. Methods : BP measurements were done on 57,433 Koean children and adolescents (male: 29,443, female: 27,990), aged 7 to 20 years, in 2005. Heights and weights were measured simultaneously. Oscillometric devices, Dinamap Procare 200 (GE Inc., Milwaukee, Wi, USA), were used for the measurements. BPs were measured 2 times and mean levels were gathered for the analysis. Outliers of 2,373 subjects with overweight per height, over ＋3SD, were excluded for the analysis. For the BP centiles adjusted by sex, age and height, fixed modified LMS method which was adopted from the mixed effect model of 2004 Task Force in NHLBI (USA) was used. Results : Normative BP tables for Korean children and adolescents adjusted for height percentiles (5th, 10th, 25th, 50th, 75th, 90th, 95th), gender (male, female) and age(7 to 18 years) were completed. Height centiles of Korean children and adolescents are available from Korean Center for Disease Control and Prevention homepage, http://www.cdc.go.kr/webcdc/. Criteria of hypertension (95th, 99th percentile) and normal range of BP (50th, 90th) adjusted for height percentiles, age and gender were made. Conclusion : This is the first study to make normative BP tables and define hypertension for the Korean children and adolescents. Reliability and accuracy of Dinamap Procare 200 oscillometer for BP measurements remains debatable.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.3
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• pp.243-248
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• 2009

Purpose: Rehabilitation of the edentulous posterior maxilla with dental implants often poses difficulty because of insufficient bone volume caused by pneumatization of the maxillary sinus and by crestal bone resorption. Sinus grafting technique was developed to increase the vertical height to overcome this problem. The present study was designed to evaluate the sinus floor augmentation with anorganic bovine bone (Bio-$cera^{TM}$) using histomorphometric and clinical measures. Patients and methods: Thirteen patients were involved in this study and underwent total 14 sinus lift procedures. Residual bone height was ${\geq}2mm$ and ${\leq}6mm$. Lateral window approach was used, with grafting using Bio-$cera^{TM}$ only(n=1) or mixed with autogenous bone from ramus and/or maxillary tuberosity(n=13). After 6 months of healing, implant sites were created with 3mm diameter trephine and biopsies taken for histomorphometric analysis. The parameters assessed were area fraction of new bone, graft material and connective tissue. Immediate and 6 months after grafting surgery, and 6 months after implantation, computed tomography (CT) was taken and the sinus graft was evaluated morphometric analysis. After implant installation at the grafted area, the clinical outcome was checked. Results: Histomorphometry was done in ten patients.Bio-$cera^{TM}$ particles were surrounded by newly formed bone. The graft particles and newly formed bone were surrounded by connective tissue including small capillaries in some fields. Imaging processing revealed $24.86{\pm}7.59%$ of new bone, $38.20{\pm}13.19%$ connective tissue, and $36.92{\pm}14.51%$ of remaining Bio-$cera^{TM}$ particles. All grafted sites received an implant, and in all cases sufficient bone height was achieved to install implants. The increase in ridge height was about $15.9{\pm}1.8mm$ immediately after operation (from 13mm to 19mm). After 6 months operation, ridge height was reduced about $11.5{\pm}13.5%$. After implant installation, average marginal bone loss after 6 months was $0.3{\pm}0.15mm$. Conclusion: Bio-$cera^{TM}$ showed new bone formation similar with Bio-$Oss^{(R)}$ histomorphometrically and appeared to be an effective bone substitute in maxillary sinus augmentation procedure with the residual bone height from 2 to 6mm.

• Radiation Oncology Journal
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• v.19 no.2
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• pp.190-198
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• 2001

Purpose : It was reported that Captopril (angiotensin converting enzyme inhibitor) had an effect to reduce the pneumonitis and pulmonary fibrosis induced by radiation in rat. We peformed this study to investigate the radioprotective effect and mechanism of Captopril. Methods and Materials : The comparison was made between the radiation only group and the combined Captopril and radiation group by examining histopathologic findings and immunohistochemical stains $(TNF\alpha\;and\;TGF\beta1)$ at 2 and 8 weeks after irradiation. Each group has 8 to 10 rats (Sprague-Dawley). 12.5 Gy of X-ray was irradiated to the left hemithorax in a single fraction. Captopril (50 mg/kg/d) mixed with water was given per oral and continuously from 1 week prior to irradiation up to 8th week of the experiment. Result : In the combined Captopril and radiation group, the histopathologic changes which were hemorrhage into alveolar space, changes of alveolar epithelium, bronchial epithelium and blood vessels, and perivascular edema were less severe than in the radisation only group at 2 weeks. At 8 weeks, the alveolar epithelial changes and perivascular edema were less prominant in the combined Captopril and radiation group. At 2 weeks, the $TNF\alpha$ expression of the combined Captopril and radiation group was markedly decreased at the alveolar epithelium (p<0.01), lymphoid tissue (p=0.06) and the macrophage of alveolar space (p<0.01) compared with the radiation only group. Furthermore the $TGF\beta1$ expression was significantly prominant at the alveolar epithelium (p<0.02) and the macrophage in alveolar space (p<0.02). At 8 weeks, the expression of $TNF\alpha\;and\;TGF\beta1$ of most sites, except $TGF\beta1$ of the macrophage of alveolar space (p=0.09), showed no significant difference between 2 groups. Conclusion : This study revealed that early lung damage induced by irradiation was reduced with the addition of Captopril in the latent and early pneumonitis phase. The expression of $TNF\alpha\;and\;TGF\beta1$ at 2 weeks and $TGF\beta1$ at 8 weeks was further decreased in the combined Captopril and radiation group than the radiation only group. From these results, it may be concluded that the proinflammatoy cytokine $(TNF\alpha)$ and fibrogenic cytokine $(TGF\beta1)$ probably play the role of the radioprotective mechanism in Captopril.

• Korean Journal of Environmental Agriculture
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• v.32 no.1
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• pp.42-47
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• 2013

BACKGROUND: As improved LEDs (Light Emitting Diode) industry and decreased the price of LEDs in Korea, some farmers try to using the RED LEDs in green house and open field to increase the production of crop under bad weather condition. The aim of this study is to find out the effect of RED and FAR-RED LEDs lighting on the fruit quality of twelve-year old 'Hongro'/M.26 apple during night after sunset. METHODS AND RESULTS: FAR-RED (730nm, 2 and 4 hour) and RED (620nm, 2 and 4 hour) with 20 LED/PCB were treated in orchard for 16 weeks from June 10 to October 10 in 2009 and 2010 with control as an comparison. In our experiments, leaf weight was significantly higher in RED LEDs than control, tended to be decreased as times of FAR-RED lighting increased. Fruit weight was increased more in RED LEDs than control in 2009 and 2010, but decreased in FAR-RED lighting compared to control in 2010. Firmness and Hunter's a value of fruit were increased in FAR-RED lighting with 2 and 4 h than control. Soluble solid contents were higher in 2 h RED and 2, 4 h FAR-RED LEDs compared to control in 2009, there was no significant difference in 2010. Acid contents were no difference among the treatments. CONCLUSION(S): In our results, we found that RED LEDs was more helpful to increase the fruit weight and FAR-RED LEDs promote to be higher hunter a value of fruit skin. So, we thought that it is necessary to more study if mixed of RED and FAR-RED lighting is more helpful to promote fruit quality of 'Hongro' apple than single lighting of RED or FAR-RED LEDs respectively.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.14 no.2
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• pp.161-170
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• 2011

Purpose: The aim of this study was to investigate the feeding patterns, use of dietary supplements, and nutrient intake of Korean toddlers. Methods: We used data for 930 toddlers who participated in the 4th Korean National Health and Nutrition Examination Survey (KNHANES) from 2007 to 2009. Feeding patterns and use of dietary supplements were assessed using standardized questionnaires, and nutrition intake was assessed using the 24 hr recall method. Results: In 2007~2009, 48.7% of toddlers used dietary supplements. Most parents (95.4%) initiated a regime of dietary supplements for their children following the advice of friends or relatives. Only 0.4% of parents followed the advice given by their doctors for dietary supplements use. In the survey of nutrient intake for toddlers, the prevalence of inadequate calcium intake was 53.9% for subjects aged 1 year, 55.2% for 2 years and 65.6% for subjects aged 3 years. The prevalence of inadequate iron intake was 52.0% for subjects aged 1 year, 48.7% for 2 years and 48.4% for subjects aged 3 years. In the survey performed on feeding patterns of toddlers during the infant period, mixed feeding accounted for 57.4%, breast feeding for 32.2%,and formula feeding for 10.4%. Sixty-five percent of toddlers began weaning between 4 and 6 months. Conclusions: This study indicated that a number of toddlers were at risk of inadequate calcium and iron intake. The role of professionals in counseling for qualified dietary intake and dietary supplement use is therefore necessary for Korean toddlers.