• Horticultural Science & Technology
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• v.29 no.5
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• pp.447-455
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• 2011

To investigate the effects of the improvement of postharvest quality on fresh tomato, antimicrobial microperforated (AMP) films were prepared and their antimicrobial abilities were observed. AMP films were made by coating different types of natural antimicrobial agents such as cinnamon, clove, and clary sage essential oils into microperforated (MP) films. Cinnamon essential oil of 10% (v/v) has proven to be very effective as inhibitor of the mold growth on tomato, compared to the clove and clary sage essential oils. Quality changes of fresh tomatoes packed using the natural AMP films (AMP10 and AMP30) and MP films (MP10 and MP30) during storage were evaluated. Total microbial growth, weight loss, firmness, lycopene content, and decay rate as the major quality parameters were monitored over 9 days at $15^{\circ}C$. The oxygen transmission rates and mechanical properties between the natural AMP and MP films were also compared. There was no significant difference in change of oxygen transmission rate, tensile strength and elongation between the AMP and MP films. For storage studies, the freshness of tomato packaged in AMP30 film was higher than that in OPP film (the control), MP10, MP30, and AMP10 films. Especially, AMP30 film exhibited high efficiency compared to the control for tomato decay during storage periods. Based on the results, the microperforation and antimicrobial properties of the packaged films may significantly affect the maintenance of an optimum gas composition within the package atmosphere for increasing the storage life and quality of produce. They were also effective on the inhibition of microbial growth by controlled release of antimicrobial agent at an appropriate rate from the package into the tomato. Natural antimicrobial agent coating microperforated films could use potential functional package as a method of extending the freshness of postharvest tomato for storage.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.692-700
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• 2016

The objective of this study was to determine the differences in fruit growth, fruit quality, and particularly the pedicel vascular bundles of 'Shigyoku' and 'Heukboseok' grapes, which appeared to be different in softening at harvest. 'Shigyoku' grape matured faster (by about 20 days) than 'Heukboseok' grape with slight fruit enlargement after veraison. However, fruit of 'Heukboseok' grapes showed remarkable enlargement in both the primary and secondary fruit enlargement periods. Hypodermal cell layers were not different after veraison in 'Shigyoku' grape, but degradation of the hypodermis cell wall continued in 'Heukboseok' grape, resulting in a gradual decline in firmness. The numbers of hypodermal cell layers in 'Shigyoku' and 'Heukboseok' grapes were 14.2 and 9.0, respectively. The average content of soluble solids in 'Shigyoku' grape ($19.5^{\circ}Brix$) was significantly ($p{\leq}0.01$) higher than that of 'Heukboseok' grape ($17.0^{\circ}Brix$). Xylem of the pedicel did not differ between the two varieties. However, average phloem area after veraison of 'Shigyoku' grape ($19044.8{\mu}m^2$) was about 1.8 fold greater than that of 'Heukboseok' grape ($10509.4{\mu}m^2$), based on the number of cells constituting the phloem. The cell number and area of the phloem might affect the accumulation of sugars, the main constituents of the cell wall, thus maintaining the firmness of grapes until late maturity. Therefore, the increased softening of 'Heukboseok' grapes at harvest might due to their phloem structure.

• Journal of Life Science
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• v.27 no.8
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• pp.909-918
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• 2017

Ice plant (Mesembryanthemum crystallinum L.) was fermented in brine in the form of mulkimchi (IPMB), and its contents of organic acid and cyclitols and biological activities were compared with those before fermentation. The pH of the IPMB continuously decreased until the sixth day of fermentation. The lactic acid yield was greatest on the fourth day. D-pinitol in ice plant mulkimchi solids (IPMS) decreased during fermentation. However, myo-inositol and D-chiro-inositol increased. The radical scavenging activities of ABTS and DPPH, in addition to the activity of FRAP, of the IPMS extract were generally higher after fermentation, with the activities highest on the fifth ($79.09{\pm}0.69%$), fourth ($87.55{\pm}1.21%$), and sixth ($78.72{\pm}0.99%$) days of fermentation, respectively, when treated with 1 mg/ml of the extract. As shown by a lipid/MA assay, antioxidant activity was generally higher after fermentation. The viability of BNL CL.2 cells damaged by t-BHP, $H_2O_2$, and ethanol was $14.19{\pm}0.98$, $13.80{\pm}2.25$, and $25.89{\pm}2.90%$, respectively. When treated with $200{\mu}g/ml$ of IPMS extract, the cell viability was $57.06{\pm}4.52%$ on the first day, and $66.06{\pm}1.36%$ on the fourth day, and $50.07{\pm}04.85%$ on the sixth day of fermentation. Hepatocyte protective effects did not increase significantly after fermentation. ${\alpha}-glucosidase$ inhibitory activity was quite high, with a range of $83.52{\pm}2.69$ to $92.79{\pm}2.16%$, and the activity increased gradually in all the groups over the fermentation period. There was no clear correlation between ${\alpha}-amylase$ inhibitory activity and fermentation.

• Journal of Food Hygiene and Safety
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• v.28 no.3
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• pp.272-278
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• 2013

To evaluate the effect of surface contaminated with Escherichia coli O157:H7 (E. coli O157:H7) on the microbiological safety of lettuce, this study was conducted to investigate the attachment, biofilm producing, survival, and cross-contamination of E. coli O157:H7 on stainless steel and polyvinyl chloride (PVC). The attachment rate of E. coli O157:H7 on PVC was 10 times higher than that on stainless steel after exposure 1 h in cell suspension. However, there was not a difference between two types of surface after exposure for 6 h and 24h. The biofilm producing of E. coli O157:H7 was TSB > 10% lettuce extracts > 1% lettuce extracts > phosphate buffer. When two kinds of materials were stored at various conditions ($20^{\circ}C$ and $30^{\circ}C$, relative humidity (RH) 43%, 69%, and 100%), the numbers of E. coli O157:H7 at $30^{\circ}C$, RH 43% or RH 69% were reduced by 5.0 log CFU/coupon within 12 h regardless of material type. Conversely, the survival of E. coli O157:H7 at RH 100% was lasted more than 5 days. In addition, the reduction rate of E. coli O157:H7 was decreased in the presence of organic matter. The transfer efficiency of E. coli O157:H7 from the contaminated surface to lettuce was dependent upon the water amount of the surface of lettuce. Especially, the transfer rate of E. coli O157:H7 was increased by 10 times in the presence of water on the lettuce surface. From this study, the retention of E. coli O157:H7 on produce contact surfaces increase the risk cross-contamination of this pathogen to produce. Thus, it is important that the surface in post harvest facility is properly washed and sanitized after working for prevention of cross-contamination from surface.

• Research in Plant Disease
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• v.22 no.2
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• pp.72-80
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• 2016

Gummy stem blight, caused by the fungus Didymella bryoniae, is major disease of watermelons worldwide. The objective of the present study was to establish an efficient screening system to identify watermelon resistant to D. bryoniae. An GSB3 isolate was prepared from a watermelon plant showing typical symptoms of gummy stem blight in Haman-gun and identified as D. bryoniae based on molecular analysis of internal transcribed spacer sequence. A simple mass-production technique of inoculum was developed based on spore production of D. bryoniae GSB3 under several incubation conditions and their virulence on watermelon plants. Resistance degrees of 22 commercial watermelon cultivars to the GSB3 isolate were evaluated. Among them, four watermelon cultivars showing different degree of resistance response were selected for further study. Development of disease on the cultivars according to various conditions including inoculum concentrations, incubation periods in dew chamber, and incubation temperatures was investigated. From the results, we suggest an efficient screening method for resistant watermelon cultivars to gummy stem blight. Seeds of watermelon cultivar are sown and grown in a greenhouse until plant stage of 2-fully expanded leaves. Seedlings are inoculated with D. bryoniae by spraying spore suspension of the fungus at a concentration of $5.0{\times}10^5spores/ml$. The infected plants are incubated in humidity chamber at $25^{\circ}C$ for 48 hours and then transferred to a growth chamber at $25^{\circ}C$ and 80% relative humidity with 12-hour light a day. Three to four days after inoculation, disease severity of the plant are measured using percentage of infected leaf area.

• Journal of Chest Surgery
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• v.37 no.9
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• pp.742-748
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• 2004

The On-X valve was recently introduced. It was the aim of this study to assess the safety and feasibility from the data derived from 28 patients who underwent aortic and/or mitral valve replacement with this prosthesis in National Medical Center. Material and Method： From May 1999 and May 2003, a series of 28 consecutive patients who had been implanted with 32 On-X prosthesis were reviewed, The operative procedure comprised of 12 MVR, 10 AVR and 6 DVR. The study followed the guidelines of AATS/STS. Mean follow-up was 27 months (total 04 patient-years). Result: Early ($\leq$30 days) mortality was 7.44% (2/28) and no late mortality occurred in the study. Total actuarial freedom from mortality at 2 years was 92.86$\pm$4.87% for all cases, 100% for MVR, 90$\pm$9.49% for AVR, and 83.3$\pm$1.52% for DVR. Thromboembolic event occurred in 2 MVR patients and that was the only complication; therefore, the linearized incidence of valve related complications was 3.17%/ patient-years for all cases and 6.5%/patient-years for MVR and the actuarial freedom from valve related complications at 2 years was 84.85$\pm$10.75%. Preoperatively, 24 (85.71%) patients were in NYHA functional class III or IV but postoperatively, 25 (89,29%) patients were in NYHA functional class I or II. The levels of hemoglobin, hematocrit, serum LDH, reticulocyte rate and indirect bilirubin were all within normal range at postoperative 3 month. In mitral position, the peak gradient was 6.1$\pm$1.8 mmHg and the mean gradient was 3.0$\pm$0.6 mmHg and EOA were 2.54$\pm$0.56 $m^2$, 2.39$\pm$0.73 $m^2$, 2.34$\pm$0.55 $m^2$, 2.40$\pm$0.63 $m^2$ at 27 mm, 29 mm, 31 mm, 33 mm respectively. In aortic postion, the peak gradient was 21.1 $\pm$14.12 mmHg and the mean gradient was 12.3$\pm$6.52 mmHg. Conclusion: Since there was no significant difference in the postoperative mortality, valve related complications and echocardiographic hemodynamic data compared to standard bileaflet design and since there was an improvement in the NYHA functional class and normal values of hemolytic indicators, it can be assumed that On-X valve is safe and feasible. However, accumulation of cases and long-term follow-up of this patient group is needed to establish this result.

• Journal of Wetlands Research
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• v.10 no.2
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• pp.115-128
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• 2008

Various human activities such as the Urbanization and Industrialization are estimated the main factors to pollute the stream. Now days, numerous studies are carried out for managing non-point sources which have un-effect on water quality of streams by land-use and livestock. In case of Korea, a matter of concern that the management of Pal dang reservoir - the main water resources of the national capital region - has been occurring. Especially, large-scale constructed-wetlands are planned and constructed at the end of Kyoung-an stream. Additionally a lot of sewage treatment plants are newly installed and extended in this watershed. According to these efforts, water quality of Kyoung-an stream is predicted that would be improved. But the more detail and scientific analysis should be carried out for the water quality improvement, because, existing water quality improvement projects are not involved to analyze root of water quality deterioration and improvement plans. Therefore, this study aims to select suitable areas for constructed-wetlands and to calculate size of the constructed-wetlands for water quality improvement in Kyoung-an stream through the geographical pollutant distribution analysis and land-use pattern analysis by high resolution satellite image and suitable area analysis of constructed-wetlands by GIS(Geographic information system). The progress of this study is (1) to select maximum pollutant loaded area by geographical analysis based on water quality data, (2) to analyze land-use patterns using high resolution satellite image, (3) to select suitable areas of constructed-wetlands, (4) to calculate area and volume of chosen constructed-wetlands using GIS. Basically, sizes of constructed-wetlands are induced through the constructed-wetlands design index based on treatment ratio(provided by Korea Water Resources Corporation). As a result of this study, two areas are selected to construct constructed-wetlands. One of the area was $127,586m^2$ near by Yong-in sewage treatment plant, and the other area was $1,647m^2$ near by Ju-buk stream and Dae-dae stream.

• Korean Journal of Microbiology
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• v.34 no.3
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• pp.154-161
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• 1998

To investigate whether the introduced genetic marker is useful to detect the survivalship and activity of the natural bacteria under the stressed conditions, one Gram-negative isolate, KP964 was transformed to the luminous phenotype by transferring luxAB gene. Under the starvation-stress this luminous bacterial culturability (determined by colony-forming-units [CFU] on agar plate) decreased rapidly below the detection limit by 37 days, while its total cell number (determined by AODC) remained almost the same as its initial inocular size. At that time period, the viable cell number was estimated to be 1400 times higher than its CFU number. The bioiuminescence (determined by relative light units [RLU]) produced under the same condition was also monitored and found to decrease more rapidly than the culturability by 5-fold. Under the other stresses, e.g., osmotic shocks, acid shock, and exposure to toxic chemicals, this bacterial strain did not show the reliable correlation between CFU and RLU. These results might not suggest the direct estimation of bioiuminescence from the stressed bacteria be an index of both the survivalship and its activity. However, when the stressed bacterial cells were incubated under the favorable condition by relieving from the existing stress, the potential bioiuminescence (the lag periods before the increase of bioiuminescence, the increase rates of bioiuminescence, and the maximal levels of bioiuminescence) was shown to be highly dependent upon the strengths of the stresses exposed to the bacterial cells. Therefore, analysis of the potential bioiuminescence from the stressed bacteria revealed good relationships with survival as well as activity.

• Journal of Nutrition and Health
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• v.8 no.4
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• pp.15-26
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• 1975

The purpose of this paper is to investigate the nutrients intake situation and the physical growth and development of junior high school girls in cheju island, the peculiar area in Korea, and to study every possible correlation ketween daily food intake and growth rate of them. Further, it made an attempt to research nutrition problems for them in this area and assist in their growth and development through proper nutritional marragement. The survey was conducted in seven sample schods selected randomly from all three districts -this is Bukcheju-gun, Namcheju-gun and cheju city-of cheju Island. Four hundred eighteen girls, aged thirteen years ald, in second year grade of junior high schools, were provided with prepared questionnaires. For six days, July $16{\sim}21$ in 1975, the respondents filled out the questionnaires. They were asked to keep record of what they ate each meat. Their mitrients intake were analyzed in accordance with their daily food intake records during a six day period. On the other side, including physical growth index calculated by means of weight and hight of the respondents, their school records were also investigated. Critical Ratio as well as percentage calculation were included for statistical analysis. The findings and results abtained are summarized as follows: (1) Living circumstance a) Average numbers of brother and sister in sampled pupils' family were five. b) Niety percent of the respondents were brought up by mother's milk at their infants and 45 percent of them were weaned at the age of 13 to 24 months. c) Fourty-six percent of them revealed irregulity in their meal time. d) The most favorite main dish was boiled rice mixed other cereals (34%), next bread (31%) and boiled noodle (26%), and kimchi was the most papular side dish (64%). (2) Nutrition survey a) The average calorie intake of a pupil per day was 1,783 cal. and the total calorie intake was composed of carbohydrate 73%, pratein 15%, fat 12% respectively. b) Carolie and nutrients were lower than the recommended level, except vitamins A,$B_1$ and Niacin, c) Average protein intake per day was 68g, which was relatively near to the recommended level, but in fact, most of them came from grain which is lacking in essential amino acids. The ratio of animal protein intake to tatal protein intake was 36%. d) Their average animal food intake was proportionated in 14% in their total food intake and the cereals consumed in the largest quantity at the level of 63% out of whole food groups. (3) The results of statistical analysis a) The correlation between the calorie intake and the physical growth index revealed statistical significancy at the level of P<.005. b) The correlation between the protein intake and the physical growth index revealed statistical significancy at the level of .01

• Horticultural Science & Technology
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• v.28 no.6
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• pp.980-984
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• 2010

Research regarding respiration rate, off-flavor related material and freshness maintenance effect of active MA mini-packaging on perilla leaves has been carried in this study. Respiration rate was highly maintained at high oxygen treatments ($CO_2:O_2:N_2$=0:30:70 and 0:50:50), higher than non-treatment and low oxygen treatments (6:2:92, 0:10:90) during the storage period, and ethylene production was relatively higher. However, off-flavor related materials, acetaldehyde and ethanol production was noticeably low. Weight losses of non-treatment and low-oxygen treatment were about 1.8 and 1.4%, respectively. At the fifth day of storage there was no weight loss. Ascorbic acid content was 13.3 mg/100 g F.W. at the first day of storage. At the third day of storage non-treatment showed the lowest value of ascorbic acid, 8.8 mg/100 g F.W. Ascorbic acid content of active MA treatment gradually decreased without a striking difference as the storage day extended. Chlorophyll content was the lowest at the fifth day of storage with non-treatment, 47.5 (SPAD-502 unit) while the active MA treatment maintained high level of chlorophyll content, 53.0. Sensory evaluation (vision) showed that marketability gradually decreased but was maintained in high oxygen treatments (0:30:70 and 0:50:50), even at the fifth day of storage. Occurrence of off-flavor in non-treatment at the fifth day of storage was extremely low, 2.6; whereas high in high oxygen treatment, 3.4. Active MA packaging maintained freshness two more days at room temperature (about $27^{\circ}C$).