• Korean Journal of Microbiology
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• v.39 no.2
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• pp.76-82
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• 2003

To prepare evolved PHB depolymerase with increased activity for PHB or P(3HB-co-3HV) compared to the activity of the original PHB depolymerase from Alcaligenes faecalis T1, random mutation of the cloned PHB depolymerase gene was performed by using a DNA shuffling method. A library of mutated PHB depolymerase genes from A. faecalis T1 was fused to the ice nucleation protein (INP) gene from Pseudomonas syringae in pJHCl 1 and approximately 7,000 transformants were isolated. Using M9 minimal medium containing PHB or P(3HB-co-3HV) as the carbon source, mutants showing alteration in PHB depolymerase activity were selected from the transformants. The PHB depolymease activity of the transformants was confirmed by the formation of halo around colony and the turbidity decrease tests using culture supermatants. The catalytic activity of PHB depolymerase of the best mutant II-4 for PHB or P(3HB-co-13 mol% 3HV) was approximately 1.8-fold and 3.2-fold, respectively, higher than that of the original PHB depolymerase. DNA sequence analysis revealed that three amino acid residues (Ala209Val, Leu258Phe, and Asp263Thr) were substituted in II-4. From the mutational analysis, it was presumed that the substitution of amino acids near catalytic triad to more hydrophobic amino acids enhance the catalytic activity of PHB depolymerase from A. faecalis T1.

• Journal of ILASS-Korea
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• v.12 no.1
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• pp.38-44
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• 2007

Since the Liquid Phase LPG injection (LPLI) system has Advantages in power generation and emission characteristics compared to the mixer-type fuel-supply system, a variety of studies regarding LPLi system has been conducted and its applications are made in automobile industry. However, the heat extraction due to the evaporation of liquid fuel, causes not only a post-accumulation of fuel but also an icing phenomenon which is a frost of moisture in the air around the nozzle tip. Since there exists a difficulty in the accurate control of air fuel ratio in both fuel supply systems, it can result in poor engine performance and a large amount of harmful emissions. This research examines the characteristics of icing phenomenon and develops anti-icing bushing to prevent an icing on the surface of the injection tip. It was found that n-butane, which has a relatively high boiling point ($-0.5^{\circ}C$), was a main species of post-accumulation. Also the results show that the post-accumulation problem was allevaited the utilization of a large inner to outer bore ratio and smooth surface roughness. In addition, an icing phenomenon and its formation process were found to be mainly affected by the humidity and the temperature of inlet air in an inlet duct. Also, it was observed that an icing phenomenon is lessened using aluminum bushing whose end coincides with the end of fuel injection tip in length.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.712-717
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• 2010

Cytochrome P450 enzymes (P450s) are involved in the synthesis of a wide variety of valuable products and in the degradation of numerous toxic compounds. The P450 BM3 (CYP102A1) from Bacillus megaterium was the first P450 discovered to be fused to its redox partner, a mammalian-like diflavin reductase. Here, we report the development of a whole-cell biocatalyst using ice-nucleation protein (Inp) from Pseudomonas syringae to display a hemeand diflavin-containing oxidoreductase, P450 BM3 (a single, 119-kDa polypeptide with domains of both an oxygenase and a reductase) on the surface of Escherichia coli. The surface localization and functionality of the fusion protein containing P450 BM3 were verified by flow cytometry and measurement of enzymatic activities. The results of this study comprise the first report of microbial cell-surface display of a heme- and diflavin-containing enzyme. This system should allow us to select and develop oxidoreductases containing heme and/or flavins into practically useful whole-cell biocatalysts for extensive biotechnological applications, including selective synthesis of new chemicals and pharmaceuticals, bioconversion, bioremediation, live vaccine development, and biochip development.

• Journal of Korean Academy of Nursing
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• v.29 no.3
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• pp.530-540
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• 1999

The purpose of this study was to investigate the life style, self-efficacy, and Bone Marrow Density (BMD) in osteoporosis female patients. The subjects were recruited at the four Osteoporosis Clinics. A convenience sample of 190 women completed a survey instrument which included the Osteoporosis Self-Efficacy Questionnaire, Life Style Questionnaire and demographic items. BMD of L$_4$ was measured by Dual Photon Absor photiometry. The sample ranged in age from 40 to 82 years (Mean＝60.28). Eighty-one percent were married and 14.9% were widowed. Forty-four percent lived with their spouse and children. Excercise, diet, medication, alcohol consumption, and smoking were measured to investigate the life style. Fifty-seven percent of the subjects exercised regularly. Mountain climbing, brisk walking, and free gymnastics were frequently cited excercises by the subjects in this study. Sixty percent drank one cup of milk and 34.7% had 1.13 cups of coffee in a day. Thirty-nine percent used calcium supplements, 9.5% drank alcohol, and 3.2% smoked cigarettes. Economic status and education level were related to self-efficacy. Age, economic status, and education level were related to BMD. As a life style, exercise, diet(milk, ice cream, and coffee), and medication(calcium) were associated with self-efficacy. The subjects who exercised regularly and took calcium supplements for a longer time had a higher level of self-efficacy than those who did not. Smoking and alcohol consumption had no relationship with self-efficacy. Excercise, medication(calcium), and alcohol consumption were related to BMD. The subjects who took calcium supplements for a longer time had a higher level of BMD. Alcohol consumption was not related to self-efficacy but related to BMD. The subject who drank alcohol had a higher level of BMD than those who did not drink. The amount of alcohol consumption was positively related to BMD.

• Atmosphere
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• v.23 no.4
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• pp.453-470
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• 2013

As a part of the KIAPS Observation Processing System (KOPS), we have developed the modules of satellite radiance data pre-processing and quality control, which include observation operators to interpolate model state variables into radiances in observation space. AMSU-A (Advanced Microwave Sounding Unit-A) level-1d radiance data have been extracted using the BUFR (Binary Universal Form for the Representation of meteorological data) decoder and a first guess has been calculated with RTTOV (Radiative Transfer for TIROS Operational Vertical Sounder) version 10.2. For initial quality checks, the pixels contaminated by large amounts of cloud liquid water, heavy precipitation, and sea ice have been removed. Channels for assimilation, rejection, or monitoring have been respectively selected for different surface types since the errors from the skin temperature are caused by inaccurate surface emissivity. Correcting the bias caused by errors in the instruments and radiative transfer model is crucial in radiance data pre-processing. We have developed bias correction modules in two steps based on 30-day innovation statistics (observed radiance minus background; O-B). The scan bias correction has been calculated individually for each channel, satellite, and scan position. Then a multiple linear regression of the scan-bias-corrected innovations with several predictors has been employed to correct the airmass bias.

• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.52-58
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• 2023

With the increasing awareness of the importance of carbon neutrality in response to global climate change, the utilization of hydrogen as a carbon-free fuel source is also growing. Hydrogen is commonly used in fuel cells (FC), but it can also be utilized in internal combustion engines (ICE) that are based on combustion. Particularly, ICEs that already have established infrastructure for production and supply can greatly contribute to the expansion of hydrogen energy utilization when it becomes difficult to rely solely on fuel cells or expand their infrastructure. However, a disadvantage of utilizing hydrogen through combustion is the potential generation of nitrogen oxides (NOx), which are harmful emissions formed when nitrogen in the air reacts with oxygen at high temperatures. In particular, for the EURO-7 exhaust regulation, which includes cold start operation, efforts to reduce exhaust emissions during the warm-up process are required. Therefore, in this study, the characteristics of nitrogen oxides and fuel consumption were investigated during the warm-up process of cooling water from room temperature to 88℃ using a 2-liter direct injection spark ignition (SI) engine fueled with hydrogen. One advantage of hydrogen, compared to conventional fuels like gasoline, natural gas, and liquefied petroleum gas (LPG), is its wide flammable range, which allows for sparser control of the excessive air ratio. In this study, the excessive air ratio was varied as 1.6/1.8/2.0 during the warm-up process, and the results were analyzed. The experimental results show that as the excessive air ratio becomes sparser during warm-up, the emission of nitrogen oxides per unit time decreases, and the thermal efficiency relatively increases. However, as the time required to reach the final temperature becomes longer, the cumulative emissions and fuel consumption may worsen.

• Journal of Nutrition and Health
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• v.16 no.1
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• pp.41-55
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• 1983

A dietary survey of young childern from one to six-year old, was conducted in summer and in winter, in Yonggin-gun, Kyunggi-do, to survey the differences in food and nutrient intake between a one day and a three day term, and between the winter and the summer season, in an attempt to provide a basis for the development of adequate dietary survey methodology. A total of 65 children originally were surveyed from July 3 to 11, 1981. However, since 9 of the 65 subjects moved away from the original addresses, 54 subjects were available for the winter-term survey, which was conducted from January 15 to 23, 1982. Among a total of 13 foods, intake of cereals (p<0.001), vegetables (p<0.05), beverage and ice candies (p<0.05) were significant in affecting the daily difference : one day vs. three days. Intakes of energy (p<0.05) and carbohydrate (p<0.05) were also significant in affecting daily difference. Among a total of 13 foods, intake of eggs, milk and milk products, sea-weeds, vegetables, cereals, potatoes, fat and oils, were significant in affecting seasonal difference : summer vs. winter. Intake of fat and ascorbic acid were also significant in affceting seasonal difference.

• Food Science of Animal Resources
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• v.24 no.4
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• pp.326-328
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• 2004

Domestic pear has been reported that it contained a pretense, which used for tenderizer of meat, however no researches for optimum level of the enzyme with maximum tenderness effect have been studied. Thus, this study was peformed to determine the optimum level of a protease for meat tenderness. Moisture contents (％) of domestic pears was determined. A pretense was homogenized in a mixer and centrifuged at 10,000 G for 1hr. After taken the supernatant, dialysis was conducted to remove salts and sugars, and freeze-dried. Then, various level (0.05, 0.1 and 0.2％) of the purified pretense were added to pork loins (3cm thickness). Then, pork samples were boiled at 80 for 12 min in a water bath to reach the interval temperature of 71 and chilled in an ice. Moisture contents (％) of domestic pears ranged from 87.2 and 87.8％. No differences in cooking loss of pork meats were observed (p>0.05) among various levels of a pretense. After centrifugation, the protein concentrations of a protease showed from 5.96 $\mu\textrm{g}$/fmL to 7.25 $\mu\textrm{g}$/mL. Increased level of a pretense up to 0.1％ reduced (p<0.05) the shear value (kg/g), however no further reduction of shear value was observed at the level of higher than 0.1％ of the purified pretense. The approximate molecular weight of the pretense analysed by sodium-dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was 30 kDa. These results suggest that the optimum level of a pretense for the maximum effect of meat tenderness is above 0.1％. Further research will be peformed to determine the effect of various domestic pears and ingredients, such as salt and phosphate, on meat tenderness.

• Atmosphere
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• v.27 no.3
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• pp.261-276
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• 2017

The main objectives of this study are to introduce Global Seasonal forecasting system version5 (GloSea5) of KMA and to evaluate the performance of ensemble prediction of system. KMA has performed an operational seasonal forecast system which is a joint system between KMA and UK Met office since 2014. GloSea5 is a fully coupled global climate model which consists of atmosphere (UM), ocean (NEMO), land surface (JULES) and sea ice (CICE) components through the coupler OASIS. The model resolution, used in GloSea5, is N216L85 (~60 km in mid-latitudes) in the atmosphere and ORCA0.25L75 ($0.25^{\circ}$ on a tri-polar grid) in the ocean. In this research, we evaluate the performance of this system using by RMSE, Correlation and MSSS for ensemble mean values. The forecast (FCST) and hindcast (HCST) are separately verified, and the operational data of GloSea5 are used from 2014 to 2015. The performance skills are similar to the past study. For example, the RMSE of h500 is increased from 22.30 gpm of 1 week forecast to 53.82 gpm of 7 week forecast but there is a similar error about 50~53 gpm after 3 week forecast. The Nino Index of SST shows a great correlation (higher than 0.9) up to 7 week forecast in Nino 3.4 area. It can be concluded that GloSea5 has a great performance for seasonal prediction.

• The Korean Journal of Food And Nutrition
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• v.21 no.3
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• pp.355-365
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• 2008

The purpose of this study was to investigate the food sanitation awareness and performance of foodservice industry employees. Based on a literature review, a questionnaire was developed to identify the food sanitation education, experience, knowledge, and food sanitation practices of the employees. A total of 376 Korean food industry employees participated, and there were 344 usable questionnaires. In the analysis of food sanitation knowledge, the statements "clip fingernails short and do not use nail polish", and "if feeling sick, even with a minor cold, speak to your supervisor immediately", had the highest and lowest percentages of correct answers, respectively. In assessing employee sanitary management practices, many correctly acknowledged "clip fingernails short and do not use nail polish" and "wash hands after using the toilet", which received high scores; however, "use hands to pick up ice" and "if feeling sick, even with a minor cold, speak to your supervisor immediately" had low scores. The sanitary knowledge and practice levels of the employees were not significantly different according to gender, age, work area, job title, or duration of duty. Among the surveyed industries, employees of special restaurants had the least sanitary knowledge(p<0.05) and practice scores(p<0.001). Employees who had worked for $1{\sim}3$ years presented the least sanitary management practice level scores(p<0.05).). In addition, college students and participants without hygiene educational experience showed the least levels of sanitary knowledge(p<0.01). Scores for sanitary management practice were higher when hygiene education was regularly conducted more than once per month. Employees showed significantly higher knowledge and sanitary management practice levels when they were required to use a sanitary checklist(p<0.001), and employees who were trained in HACCP had significantly higher sanitary checklist scores(p<0.05). In foodservices that applied HACCP, the employees showed higher knowledge and sanitary management practice levels(p<0.001).