• Clean Technology
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• v.22 no.1
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• pp.53-61
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• 2016

Steam reforming of tar produced from biomass gasification was conducted using several Ni-based catalysts. In labscale, the catalytic steam reforming of toluene which is a major component of biomass tar was studied. A fixed bed reactor was used at various temperatures of 400-800 ℃. Ru (0.6 wt%) and Mn or K (1 wt%) were applied as a promoter in Ni based catalysts. Generally, Ni/Ru-K/Al₂O₃ catalyst shows higher performance on steam reforming of toluene than Ni/Ru-Mn/Al₂O₃ catalyst. Used catalysts were analyzed by XRD and TGA to detect sintering and carbon deposition. Base on the lab-scale studies, the monolith and pellet type catalysts were tested in 1 ton/day scale biomass gasification system. Ni/Ru-K/Al₂O₃ monolith catalyst shows high tar reforming performance at high temperature. In addition, Ni/Ru-Mn/Al₂O₃ monolith catalyst was showed deactivation with operation time. Reforming performance of Ni/Ru-K/Al₂O₃ pellet catalyst which showed 66.7% tar conversion at 587 ℃ was compared to regenerated one. Overall, Ni/Ru-K/Al₂O₃ pellet catalyst shows higher stability and performance than other used catalysts.

• Childhood Kidney Diseases
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• v.3 no.1
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• pp.57-63
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• 1999

Purpose : To evaluate the diagnostic significance of simultaneous examination of hematuria and proteinuria in the urinary mass screening for early detection ot incipient renal diseases. Method and Object : During the period of 4 months from August to December in 1997, we did urinary mass screening on students of first grade of high school (16 years aged group) nationwide together with Korean Association of Health(KAH). In the first screening test, Comber-10 $N^{(R)}$ M dipsticks were used to detect proteinuria, hematuria, pyuria and nitrite simultaneously. Total 26,508 students (16 years aged group) from 33 high schools in every province in Korea, respectively, complied to the urinary mass screening. After then, one high school in Seoul was selected to reveal the true incidence of incipient renal diseases among students who showed hematuria in the initial screening through intensive examinations. Those who had hematuria and/or proteinuria visited the Paik hospital, and underwent blood tests and ultrasonographic examinations. The results were evaluated. Results 1) The initial screening revealed that the prevalence of proteinuria, hematuria, pyuria and positive nitrite urine, were $0.73\%,\;2.69\%,\;0.23\%\;and\;0.03\%$, respectively. 2) The first urinary screening among 875 students from one high school in Seoul selected fir the second test showed proteinuria, hematuria, pyuria and positive nitrite urine, were $0.91\%,\;4.68\%,\;0.34\%\;and\;0\%$, respectively. a) Total 8 among 875 students showed proteinuria, but one of them had orthostatic proteinuria and those remaining 7 students had transient proteinuria. b) There were 41 students who had hematuria in the initial screening. Among 33 who complied the second test, only one student showed asymptomatic isolated hematuria and those remaining students were normal. Conclusion : 1) Because of high false positive hematuria rate in the urinary mass screening, it dosen't seem to be appropriate that hematuria screening using dipsticks be included in the urinary mass screening. 2) A unified organization is needed from the fret that so various results of urinary mass screening came out. 3) Positive rates of pyuria and nitrite were so low that validity of urinary mass screening for urinary tract infection needs more studies.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.3-7
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• 2010

Purpose: The usefulness of Positron Emission Tomography (PET) images in diagnosis, staging, recurrent and treatment response evaluation has already been known. However, tumors which are small size, located in lower lobe of lung or upper lobe of liver are shown misalignment, distortion and different Standard Uptake Value (SUV) by respiration in PET images. Therefore, if radiotherapy based on normal respiration, it may cause low treatment response or more side effects because targets which had to treat, out of treat range or over dose to normal tissue. The purpose of this study is to evaluate attenuation-correction with Average CT (ACT) for more accuracy SUV measurement and minimize artifact by respiration. Materials and Methods: 13 patients, who had tumors which are around the diaphragm, underwent ACT scan after Helical CT (HCT) scan with PET/CT (Discovery DSTE 8; GE Healthcare). We quantified the differences between attenuation corrected image with HCT and attenuation corrected image with ACT in artifact size and maximum SUV ($SUV_{max}$). Artifacts were evaluated by measurement of the curved photogenic area in the lower thorax of the PET images for all patients. $SUV_{max}$ was measured separately at the primary tumors. Analysis program was Advantage Workstation v4.3 (GE Healthcare). Patients were injected with 7.4 MBq (0.2 $mC_i$) per kg of $^{18}F$-FDG and scanned 1 hour after injection. The PET acquisition was 3 minute per bed. Results: Significantly lower artifact were observed in PET/ACT images than in PET/HCT images (below-thoracic artifacts caused by under corrected $1.5{\pm}3.5$ cm vs. $13.4{\pm}4.2$ cm). Significantly higher $SUV_{max}$ were noted in PET/ACT images than in PET/HCT images in the primary tumor. Compared with PET/HCT images, $SUV_{max}$ in PET/ACT images were higher by $5.3{\pm}3.9%$ (mean value) tumor. The highest difference was observed in Lower lobe of lung (7.7 to 8.7; 13%). Conclusion: Due to its significantly reduced artifacts in lower thoracic, attenuation corrected image with ACT images provided more reliable $SUV_{max}$ and may be helpful in monitoring treatment response. Moreover, ACT can separate upper lobe of liver and lower lobe of lung, it may be helpful in interpretation. ACT will be clinically useful, considering increased dose caused by ACT scan and adapt.

• Pediatric Infection and Vaccine
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• v.26 no.3
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• pp.179-187
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• 2019

Purpose: Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome is a leading cause of periodic fever in children. This study describes the clinical characteristics of PFAPA syndrome in patients from a single center. Methods: Thirteen children diagnosed with PFAPA syndrome at Seoul National University Children's Hospital were included in this study. Retrospective medical chart reviews were performed. Results: Among the 13 patients, 8 (61.5%) were male. The median follow-up duration was 3.3 years (range, 10 months-8.3 years). The median age of periodic fever onset was 3 years (range, 1-6 years). All patients had at least 5 episodes of periodic fever and pharyngitis, managed with oral antibiotics, before diagnosis. The median occurrence of fever was every 3.9 weeks and lasted for 4.2 days. All patients had pharyngitis and 12 (92.3%) had cervical lymphadenitis. Blood tests were performed for 12 patients, and no patients had neutropenia. Both the C-reactive protein and erythrocyte sedimentation rate were elevated at medians of 4.5 mg/dL (range, 0.4-13.2 mg/dL) and 29 mm/hr (range, 16-49 mm/hr), respectively. Throat swab cultures and rapid streptococcal antigen tests were negative. Nine (69.2%) patients received oral prednisolone at a median dose of 0.8 mg/kg, and in 6 (66.7%) patients, fever resolved within a few hours. Three (23.1%) patients received tonsillectomy and adenoidectomy. Conclusions: PFAPA syndrome should be considered when a child presents with periodic fever along with aphthous stomatitis, pharyngitis, or cervical lymphadenitis. Glucocorticoid administration is effective for fever resolution and can reduce unnecessary use of antibiotics.

• Radiation Oncology Journal
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• v.15 no.3
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• pp.187-195
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• 1997

Purpose : To analyze the involvement of apoptosis regulatory genes p53, $p21^{wart/cip1}$ bax and bcl-2 in induction of apoptosis by radiation in murine tumors. Materials and methods : The radiation-sensitive ovarian carcinoma OCa-1, and the radiation-resistant hepatocarcinorna HCa-I were used. Tumors, 8 mm in diameter, were irradiated with 25 Gy and at various times after irradiation, ranging from 1 to 48 h, were analyzed histologically for apoptosis and by western blot for alterations in the expression of these genes. The p53 status of the tumors were determined by the polymerase chain reaction-single strand conformation polymorphism assay. Results : Both tumors were positive for wild-type p53. Radiation inducesd apoptosis in OCa-1 but not in HCa-1. Apoptosis developed rapidly, peaked at 2 h after irradiation and returned to almost the background level at 48 h In OCa-1 radiation upregulated the expression of p53, $p21^{wart/cip1}$. and the bcl-2/bax ratio was decreased. In HCa-1 radiation increased the expression of both p53 and $p21^{wart/cip1}$, although the increase of the latter was small The bcl-2/bax ratio was greatly increased. In general the observed changes occurred within a few hours after irradiation, and either preceded or coincided with development of apoptosis Conclusions : The development of apoptosis required upregulation of both p53 and $p21^{wart/cip1}$ as well as a decrease in bcl-2/bax ratio. In contrast, an increase in bcl-2/bax ratio Prevented apoptosis in the presence of upregulated p53 and $p21^{wart/cip1}$ . These findings indentified the involvement of multiple oncogenes in apoptosis regulation in vivo and demonstrate the complexity that may be associated with the use of a single oncogene assessment for Predicting the outcome of cancer therapy with cytotoxic agents.

• Journal of Food Hygiene and Safety
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• v.17 no.1
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• pp.36-44
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• 2002

GC-l00X is non-corrosive alkaline ionic water (pH 12). It is composed of hydroxyl radicals and supplemented with xylitol. Its antimicrobial activity was examined against 6 major food-borne pathogens; Staphylococcus aureus FRI 913, Salmonella enterica serova Enteritidis ATCC 13076, S. enterica serova Typhimurium Korean isolate, Vibrio parahaemolyticus ATCC 17803, Escherichia coli O157:H7 ATCC 43894 and Pseudomonas aeruginosa KCTC 1637 at three different temperatures (4$^{\circ}C$, $25^{\circ}C$ and 36$^{\circ}C$) with or without an organic material (2% yeast extract), respectively. The antimicrobial activities showed over 4 log-reductions (1.0$\times$10$^4$CFU/ml reduction) against all pathogens reacted at 37$^{\circ}C$ for 3 hours in the absence of the organic material. The activities showed same results when GC-l00X was diluted with same volume of distilled water or standard hard water (CaCO$_3$300 ppm). Its antimicrobial activity was more effective and quicker in Gram-negative bacteria than Gram-positive bacteria. Its washing efficacy against E. coli O157:H7 exposed to the surfaces of tomatoes (grapes) was compared with that of the other sanitizers such as other kitchen synthetic detergent and 100-ppm chlorine water. For the toxicological evaluation of the sanitizers, viable counts of E. coli O157:H7 penetrated into the core of tomatoes after washing products were also compared. The result revealed that GC-100X stock solution and its 5% diluted solution had similar washing effects to 100-ppm chlorine water and more effective than the other kitchen synthetic detergent. This result indicated that GC- l00X had antimicrobial activity and no toxicological side effects, therefore, could be useful for a new sanitizer to use in flood safety and kitchen hygiene.

• Journal of Soil and Groundwater Environment
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• v.10 no.3
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• pp.38-45
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• 2005

The feasibility of stimulating in situ aerobic cometabolic activity of indigenous microorganisms was investigated in a trichloroethylene (TCE)-contaminated aquifer. A series of single-well natural drift tests (SWNDTs) was conducted by injecting site groundwater amended with a bromide tracer and combinations of toluene, oxygen, nitrate, ethylene and TCE into an existing monitoring well and by sampling the same well over time. Three field tests, Push-pull Transport Test, Drift Biostimulation Test, and Drift Surrogate Activity Test, were performed in sequence. Initial rate of toluene degradation was much faster than the rate of bromide dilution resulting from natural groundwater drift, indicating stimulation of indigenous toluene-oxidizing microorganisms. Transformation of ethylene, a surrogate probing overall activity of TCE transformation, was also observed, and its transformation results in the production of ethylene oxide, suggesting that some tolueneoxidizing microorganisms stimulated may express a orthomonooxygenase enzyme. Also in situ transformation of TCE was confirmed by greater retardation of TCE than bromide after the stimulation of toluene-oxidizing microorganisms. These results indicate that, in this environment, toluene and oxygen additions stimulated the growth and aerobic cometabolic activity of indigenous microorganisms expressing orthomonooxygenase enzymes. The simple, low-cost field test method presented in this study provides an effective method for conducting rapid field assessments and pilot testing of aerobic cometabolism, which has previously hindered application of this technology to groundwater remediation.

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.468-474
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• 1993

A dehydrating sheet comprises polymeric water absorber. which are packed in a semipermeable cellophane film bag allowing selective permeation of water. This sheet dehydration is quite different from conventional drying method such as sun drying, hot-air blast drying and cold air blast drying in a sense that samples are dried without heat treatment. As a part of the studies to develope a new processing method for effective utilization of dark muscle fishes, the preparation of a good quality salted and semi-dried mackerel by the dehydrating sheet was attempted. The dehydration time for preparation of a salted and semi-dried mackerels containing approximately equal moisture content were revealed $180{\sim}510min$ in conventional drying method and $90{\sim}160min$ in this sheet dehydration, respectively. The moisture and histamine contents of those salted and semi-dried mackerels were $59.4{\sim}62.4%$ and $2.5{\sim}3.6 mg/100g$, respectively. The changes in peroxide value, fatty acid composition, brown pigment formation, myofibrillar protein solubility and Ca-ATPase activity during processing of the salted and semi-dried mackerel prepared by the sheet dehydration were more lower than those of products prepared by conventional drying methods. Therefore, these result showed that the quality of a salted and semi-dried mackerel prepared by the sheet dehydration was imperial to that of those products by conventional drying method.

• Journal of Food Hygiene and Safety
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• v.33 no.5
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• pp.361-368
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• 2018

N-nitrosamines are probable or possible human carcinogens, which are produced by the reaction between secondary amines and nitrogen oxide in the acidic environment or by heating. Common risk assessment procedure involves the comparison between exposures expressed in the unit, mg/kg body weight/day and the Health-Based Reference dose expressed in the same unit. This procedure is suitable for the policy decision-making and is considered as inappropriate for the consumers to get information about their dietary decision-making. Therefore, the distributions of NDMA (N-nitrosodimethylamine), NDBA (N-nitrosodibutylamine), the six N-nitrosamines (NDMA, NDBA, NDEA (N-nitrosodiethylamine), NPYR (N-nitrosopyrrolidine), NPIP (N-nitrosopiperidine), and NMOR (N-nitrosomorpholine) in the menus grouped based on the presence of main ingredients and cooking methods were analyzed to generate consumer-friendly information regarding food contaminants. Recipes and intakes were taken from 2014 to 2016 KNHANES (The Korean National Health and Nutrition Examination Survey) and only the data from ages of 7 years or older were used. The contamination data were collected from the 2014~2016 Total Diet Study and all the analysis were performed using R software. Rockfish, eel, anchovy broth and pollock were mainly exposed to N-nitrosamines. In terms of cooking methods, soups and stews appeared to contain the highest amount of N-nitrosamines. Cereals, fruits, and dairy products in the ingredient categories, and rice dishes and rice combined with others in recipe categories had the lowest level exposure to N-nitrosamines. In case of N-nitrosamines, unlike other cooking related food contaminants, boiled dishes such as soups and stews and dishes mainly consisting of fishes and shellfishes had highest level of exposure, showing a large discrepancy with the previous thought of processed meat is the main source of N-nitrosamines.

• Journal of Gifted/Talented Education
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• v.22 no.3
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• pp.575-596
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• 2012

Students' perception on a science program for gifted was investigated. The whole program was designed in consistency and integrity based on the Autonomous Learner Model suggested by Betts & Kercher(1999). 7th, 8th and 9th grade students were enrolled in this program, offered by G Education Institute for Gifted(GEI) located in Seoul. A survey was done to ask students' perception regarding the effect of the program. The survey consisted of statements about the expected effects of the program and students were asked if they agreed with the statements. Most students strongly agreed that GEI's program has positive effects. Students replied that they learned useful and interesting science contents, enjoyed meaningful experience of cooperating with members in small groups, and were challenged by the inquiry tasks. They recognized that they were being trained to become autonomous learners. They also said that their choices and decisions were respected, which resulted in positive effects on their ability to negotiate or to inquire actively. These implies that Autonomous Learner Model had been successfully applied. Although it was not clear autonomy of students was fully grown, the possibility of becoming an autonomous learner was evident. Satisfaction level is higher for the older students, implying that the integrity in the program gave accumulating effect. Students response showed that three sub-programs of GEI, the classes of each subject, conference at the end of the year and autonomous learner training played equally important role for students to learn the process of scientific inquiry and autonomous learning. This was a positive sign that the strategies for scientific inquiry and autonomous learning were embedded and integrated deeply in the program. The results of current research suggests that the integrity of a program based on a specific education model for the gifted could provide better education environment for the gifted students.