• Journal of Food Hygiene and Safety
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• v.29 no.2
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• pp.131-140
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• 2014

The objective of this study was to develop a simultaneous method of 8 penicillin antibiotics including amoxicillin, ampicillin, cloxacillin, dicloxacillin, nafcillin, oxacillin, penicillin G and penicillin V in meat using LC-MS/MS. The procedure involves solid phase extraction with HLB cartridge and subsequent analysis by LC-MS/MS. To optimize MS analytical condition of 8 compounds, each parameter was established by multiple reaction monitoring in positive ion mode. The chromatographic separation was achieved on a $C_{18}$ column with a mobile phase of 0.05% formic acid and 0.05% formic acid in acetonitrile at a flow rate of 0.2 mL/min for 20 min with a gradient elution. The developed method was validated for specificity, linearity, accuracy and precision in beef, pork and chicken. The recoveries were 71.0~106%, and relative standard deviations (RSD) were 4.0~11.2%. The limit of detection (LOD) and the limit of quantification (LOQ) were 0.003~0.008 mg/kg and 0.01~0.03 mg/kg, respectively, that are below maximum residue limit (MRL) of the penicillins. This study also performed survey of residual penicillin antibiotics for 193 samples of beef, pork and chicken collected from 9 cities in Korea. Penicillins were not found in all the samples except a sample of pork which contained cloxacillin (concentration of 0.08 mg/kg) below the MRL (0.3 mg/kg).

• Journal of Food Hygiene and Safety
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• v.29 no.2
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• pp.141-145
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• 2014

To assess the health risk for benzo(a)pyrene by the intake of edible oils, 288 cases of edible oils collected from food markets were analysed using the high performance liquid chromatography with fluorescence detector. The levels of benzo(a)pyrene were from non-detection to $4.78{\mu}g/kg$, and the average was $0.11{\mu}g/kg$. The chronic daily exposures of benzo(a)pyrene for total population group and consumer-only group were estimated using the food consumption data in the fifth Korea National Health and Nutrition Examination Survey in 2011. The estimated daily intake of benzo(a)pyrene was $4.26{\times}10^{-3}ng/kg$ b.w./day for total population group and $7.64{\times}10^{-3}ng/kg$ b.w./day for consumer-only group. The MOE (margin of exposure) of benzo(a)pyrene for total population group and consumer-only group was $7.28{\times}10^7{\sim}1.74{\times}10^8$ and $3.95{\times}10^7{\sim}9.42{\times}10^7$, respectively. Accordingly, the health risk from benzo(a)pyrene caused by the intake of edible oils was considered as a very low level.

• Journal of Gifted/Talented Education
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• v.13 no.4
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• pp.65-94
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• 2003

The purpose of this study is to acquire the information on the current situation of students' selection process in order to renovate the system of picking up the students. As a first step of the study, we examined the validity of the factors of the single-out system such as qualification and the process for the application and the standards and proceeding of the selection. Then we analysed the result of the entrance examination of Hansung Science Highschool in 2002. The analysis was on the correlation between the result of entrance examination and the achievement in the school and the decision of the course after graduation. To know on the achievement of the students, we investigated the records of regular tests and asked the teachers' opinion in math and science classes. As a result, we gained the following points: First, the present single-out system has a danger of excluding students who are much talented in science and math field because it is based on students' achievements in middle schools; Second, the new selection system should consider the character and attitude of the applicants in addition to their knowledge; Third, the continuous observation of the teacher in middle school should be an important factor of the picking up system; Fourth, more questions requiring divergent thinking ability and inquiry skill should be developed as selective examination question. Also examination questions should cover the various contents from mathematics to science, and do not affect pre-learning; Finally, the system of present letting all students stand in one line should be changed into that of letting students in various lines. We can consider using multi-step selection system.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.1140-1144
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• 2002

Molecular relaxation behaviors of crystalline glucose anhydrous, crystalline glucose monohydrate, and amorphous glucose with different particle sizes were observed by measuring spin-spin relaxation time constant $(T_2)$ at the temperature range of $-20\;to\;110^{\circ}C$ using temperature-controlled low field nuclear magnetic resonance spectroscopy. No change in $T_2$ values of crystalline glucose anhydrous was observed throughout the temperature range, whereas $T_2$ values of crystalline glucose monohydrate and amorphous glucose increased from around $45\;and\;65^{\circ}C$, respectively. These results indicate that molecular mobility of crystalline glucose anhydrous does not change even at temperature higher than $100^{\circ}C$ and that the stability of powdered glucose could be improved by increasing the particle size of materials.

• Journal of Nutrition and Health
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• v.31 no.7
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• pp.1139-1150
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• 1998

The purpose of this study is to investigate the effects of the silkworm powder on blood levels of glucose, Hb Alc, insulin, and lipids. Thirty-one NIDDM patients from Kyung Hee Medical Center were divided into two groups : patients with silkworm powder supplements and drug treatments(Drug diabetes) and patients with silkworm powder supplement only(Non-drug diabetes). For the control group, age-matched subjects were recruited. During the 4 weeks of the experimental period, silkworm powder(500mg/mea1) was given to the subjects right after each meal. Nutritional assessments and dietary education were carried out periodically, and body weight and blood pressure were measured when patients visited the hospital. Overnight fasting and 2-h postprandial blood glucose levels were measured at 2 week intervals. The blood levels of insulin, Hb Alc, and lipids were measured before and after the supplements. The mean ages of the three groups were 56.7-59.6 years old. The height, weight, and BMI did not differ among the groups. The fasting blood glucose levels were 138.1$\pm$22.0mg/dl for the Drug treated diabetes group, 175.0$\pm$32.0mg/dl for the Non-drug diabetes group, and 108. 3$\pm$16.gmg/dl for the control group at the begining of the supplement. After 4-wks of supplements, the blood levels of glucose tended to decrease in all three experimental groups. Before the supplements, the 2-h postprandial blood glucose levels of the Drug diabetes, Non drug diabetes, and control groups were 244.7$\pm$62.6mg/dl, 272.4$\pm$40.1mg/dl, and 147.7$\pm$28.0mg/dl, respectively. After the supplement, the levels were 197.2$\pm$30.gmg/dl, 208.6$\pm$ 56.6mg/dl, and 151.3$\pm$30.3mg/dl, respectively. This shows that silkworm powder tended to lower blood levels by 19.4% and 23.4% in NIDDM patient groups. However, the changes in the blood levels of insulin, Hb Alc, ind lipids were not observed after the supplement. In conclusion, the present study has demonstrated that silkworm powder has a tendency to decrease 2-h postprandial blood glucose levels, but it should be used with caution in controlling the diabetes. (Korean J Nutrition 31(7) 1139-1150, 1998)

• Journal of Nutrition and Health
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• v.51 no.1
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• pp.103-119
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• 2018

Purpose: This study was implemented to develop and validate the semi-quantitative food frequency questionnaire (SQ-FFQ) to assess energy, carbohydrates, fat, protein, minerals, and vitamins as well as fatty acids and alcohol in Korean adults. Methods: The SQ-FFQ consisted of 88 food items, and 12 food groups were selected based on information of frequently consumed foods from the Korean Health and Nutrition Examination survey. Each portion size was categorized as one of three amounts: small (0.5 times), medium (1 time), and large (1.5 times). A total of 111 subjects finished 3-day diet records and the SQ-FFQ. The relative validity of SQ-FFQ was assessed by comparison with the 3-day diet records. Results: The mean nutrient intakes obtained from the SQ-FFQ were estimated to be greater than those of the two 3-day dietary records. Spearman's correlation coefficient between the two methods was the highest for energy (r = 0.583; p < 0.001) and lowest for saturated fatty acid (r = 0.121). Correlation coefficients were energy (r = 0.583; p < 0.001), carbohydrates (r = 0.500; p < 0.001), protein (r = 0.466; p < 0.001), fat (r = 0.411; p < 0.001), dietary fiber (r = 0.467; p < 0.001), alcohol (r = 0.527; p < 0.001), calcium (r = 0.409; p < 0.001), phosphorus (r = 0.499; p < 0.001), potassium (r = 0.418; p < 0.001), magnesium (r = 0.427; p < 0.001), and zinc (r = 0.464; p < 0.001), respectively, for all subjects. Conclusion: The developed SQ-FFQ in this study seems to be useful for estimating nutritional status, particularly energy, carbohydrates, protein, fat, dietary fiber, alcohol, calcium, phosphorus, potassium, magnesium, and zinc of Korean adults.

• Current Research on Agriculture and Life Sciences
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• v.5
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• pp.119-126
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• 1987

This study was conducted to elucidate the most appropriate method to obtain auxotrophic mutants from Valsa ceratosperma, the causal fungus of apple canker, which may be used as a gene marker in detecting the transfer of the factors of avirulent strains to virulent strains. Among the 3 kinds of synthetic media tested, each have two formula for minimal and complete, the medium which has been used in study of Endothia parasitica (E. P medium) was turned out to be most appropriate for the growth of V. ceratosperma. A medium for single colony formation from pycnidiospore of this fungus was developed by adding 0.5% L - sorbose to the E. P minimal medium. The period of incubation in dark for preventing the photoreactivation after U. V irradiation was estimated as about 60hrs at which most of the spores become binucleate. Largest number of putative auxotrophs were obtained at about 50second of irradiation to the spores smeared on the medium for single colony formation, at which the survival rate of spores was 5 to 6 percent. With these method developed in this experiment, 161 isolates of putative auxotrophs were detected among which the nutrient requirement for 10 isolates were determined. Five out of 10 mutants were still virulent to apple tree and all but one could not sporulate.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.481-487
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• 1999

The optimal conditions of enzymatic hydrolysis for preparation of rapid salted and fermented anchovy sauce (SFAS) using various pretenses such as trypsin, chymotrypsin, crude enzyme from squid liver and viscera, Alcalase, Neutrase and Protamex were studied. SFAS prepared with squid viscera had higher level of VBN (173.6 mg/100 g) when stored for 70 days than other samples, and peroxide values were almost equal among all samples during fermentation period. Total amino acids and nonprotein nitrogenous compounds remarkably increased as SFAS treated with Alcalase or Protamex which exhibited higher the hydrolysis rate of $57\%$ at 60 day than others. The optimal pHs of trypsin, chymotryosin, Alcalase, Neutrase and Protamex on anchovy actomyosin were 7.5, 6.5, 6.5, 7.0 and 5.0, respectively. Optimal temperatures of trypsin, chymotryosin, Alcalase and Neutrase were 55, 45, 60 and $55^{\circ}C$, respectively. Otherwise, Protamex activity increased as temperature increased from 20 to $70^{\circ}C$. Protamex had higher $K_m$ (3.545) and $V_{max}$ value (2.688) than others. Protamex affected less by NaCl had $52.5\%$ activity at the fermentation condition of $20^{\circ}C$ and $25\%$ NaCl. Protamex appeared to be very effective for the hydrolysis of crude actomyosin from ancnovy.

• Journal of the Korean Institute of Gas
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• v.8 no.2 s.23
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• pp.15-27
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• 2004

The purpose of this paper is to improve the performance of Polymer electrolyte fuel cell(PEMFC) by studying the channel dimension of bipolar plates using commercial CFD program 'Fluent'. Simulations are done ranging from 0.5 to 3.0mm for different size in order to find the channel size which shoves the highst hydrogen consumption. The results showed that the smaller channel width, land width, channel depth, the higher hydrogen consumption in anode. When channel width is increased, the pressure drop in channel is decreased because total channel length Is decreased, and when land width is increased, the net hydrogen consumption is decreased because hydrogen is diffused under the land width. It is also found that the influence of hydrogen consumption is larger at different channel width than it at different land width. The change of hydrogen consumption with different channel depth isn't as large as it with different channel width, but channel depth has to be small as can as it does because it has influence on the volume of bipolar plates. however the hydrogen utilization among the channel sizes more than 1.0mm which can be machined in reality is the most at channel width 1.0, land width 1.0, channel depth 0.5mm and considered as optimum channel size. The fuel cell combined with 2cm${\times}$2cm diagonal or serpentine type flow field and MEA(Membrane Electrode Assembly) is tested using 100W PEMFC test station to confirm that the channel size studied in simulation. The results showed that diagonal and serpentine flow field have similarly high OCV and current density of diagonal (low field is higher($2-40mA/m^2$) than that of serpentine flow field under 0.6 voltage, but the current density of serpentine type has higher performance($5-10mA/m^2$) than that of diagonal flow field under 0.7-0.8 voltage.

• Anxiety and mood
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• v.7 no.1
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• pp.48-53
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• 2011

Objective : Korean Version of Beck-II Depression Inventory to verify the reliability and validity of the proposed standards are practical and standardized, cut-off score by establishing a baseline indicating the presence of depression and depression On in the evaluation was to evaluate the clinical usefulness. Methods : 739 patients with major depression using the SCID and normal controls were 302 study subjects. Of patients with clinically significant medical condition, or psychotic disorders, organic mental disorder, epilepsy or seizure disorder, eating disorders are associated with patients taking anti-convulsants experienced in the past, patients were excluded from the study. Results : The main findings of this study were as follows. First, with respect to the KBDI-II items, the correlation between them ranged from 0.51 to 0.74, and was 0.60 over all questions. Further, the overall correlation of the KBDI-II plates showing confidence 'normal' than it was verified that. Second, the BDIII was used in each group to examine internal consistency and thus, whether Cronbach's alpha values were greater than 0.94. Third, the principal component analysis sought to extract factors in a way consistent with the results inspected last 3 factors were extracted and the total variance explained was 47.3%. Fourth, the Cutting calculated the score on the KBDI-II for ROC (Receiver operator characteristic) analysis yielding 18 dot, with the highest sensitivity and specificity was seen. Conclusion : Based on the results of this Study, the KBDI-II cut-off point should be valid as prescribed in 18 is considered.