• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4450-4458
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• 2011

The aim of this study was to investigate the capacity of the xylitol-sensitive(Xs) and xylitol-resistant(Xr) S. mutans to induce dental caries in the presence of various carbohydrate. S. mutans KCTC3065 was cultured with 0.4% glucose and 1% xylitol in TYE medium for 30 days at $37^{\circ}C$, 10% $CO_2$ to form Xr S. mutans. Both Xs and Xr strains were cultured in four different carbohydrate environments; 0.5% glucose containing basal culture TYE medium(G-TYE), G-TYE plus 0.5% sucorse, G-TYE plus 0.5% fructose, G-TYE plus 0.5% maltose. Then cell growth, acid production, and extracellular polysaccharides synthesis were analyzed. The final growth level and extracellular polysaccharides contents in the Xr strain were significantly lower than in the Xs strain in all carbohydrates except fructose. While, acid production was no significantly difference between Xs and Xr strain. These results indicate that the virulence of Xr strains is significantly lower than that of Xs strains, which supports Xr strains may be less cariogenic than Xs strains.

• Journal of Food Hygiene and Safety
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• v.28 no.2
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• pp.181-187
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• 2013

Identification of main ingredients in starches has been investigated using physicochemical analysis method mainly. However, physicochemical properties such as particle size have limitations in determining the differences among mixed starches. Therefore, we developed a molecular biological method to identify materials used in starch, as a sample, 11 kinds of starches including sweet potato starch, potato starch, corn starch, and tapioca starch. DNeasy plant mini kit, magnetic DNA purification system, and CTAB methods were used to extract DNA from samples. After gene extraction, whole genome amplification (WGA) was performed to amplify the extracted DNA. Species-specific primers were used as followings: ib-286-F/ib-286-R (105 bp), Pss 01n-5'/Pss 01n-3' (216 bp), SS11b 3-5'/SS11b 3-3' (114 bp), and SSRY26-F/SSRY26-R (121 bp) gene for sweet potato, potato, corn, and tapioca, respectively. In this study, we could confirm the main ingredients using WGA and PCR method.

• Parasites, Hosts and Diseases
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• v.33 no.1
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• pp.37-44
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• 1995

Neodiplostomum seoulensis, one of the human intestinal trematodes , was reinfected to albino rats, and worm recovery rates, histopathology and activity changes of the intestinal brush border membrane bound enzymes were observed. The experimental groups were three: uninfected, primary infection and reinfection. The worm recovery rate in the reinfection group was much lower than in the primary infection group 14 days after infection. The duodenal histopathology showed villous atrophy during the first and second week in the primary infection group. In the reinfection group, however. villous changes occurred as early as 3 days after the infection, and the lesion was found healed 7 days after infection. The activities of alkaline phosphatase and sucrase in the duodenum of primary infection rats decreased nearly half of the controls 2 weeks after infection, whereas the activities were unchanged in the reinfection group. However, no changes in the activities were observed in the proximal jejunum between the experimental groups. These findings suggested that a secondary infection of N. seouLensis in rats should make less damage on the intestinal mucosa than a primary infection. Key words: Neoniplostomum seoulensis, albino rats, reinfection, worm recovery, histopathology, brush border membrane bound enxyines.

• Applied Biological Chemistry
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• v.37 no.3
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• pp.161-167
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• 1994

Soluble solids $(^{\circ}Brix)$, acid content and vitamin C content of Citrus miyakawa unshiu and C. okitsu unshiu juice harvested middle of November 1993 in Seuho-Dong and Topyung-Dong, Seogwipo-si, south area of Cheju were $10.7{\sim}11.0$, 1.04% and $41.19{\sim}44.94\;mg/100\;g$ juice, respectively. Carbohydrate was consisted of about 1/2 sucrose, 1/4 glucose, and 1/4 fructose. Fruit weight, peel thickness, soluble solids, pH, acid content and Brix/Acid ratio had a good correlation in linear function with increasing fruit size, respectively. However, hardness and edible part ratio were not showed correlation with increasing fruit size. Middle size of citrus fruit was favorable to panelists, and the citrus peel color of red yellow was more favorable than pale yellow color in sensory evaluation. Sensory evaluation score showed a linear correlation among citrus fruits of C. okitsu unshiu produced in Namwon-ri, Seuho-Dong, Seogwipo-si, south area of Cheju, and that of Chochun-ri, Ara-Dong, Cheju-si, north area of Cheju, and the score was higher according to citrus fruit produced in optimum cultivation area. With increasing Brix/Acid ratio of citrus juice, high sensory evaluation score was gained in panelists. These data obtained are supposed to be applied to the quality evaluation of Citrus unshiu produced in Cheju.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.196-202
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• 2008

To establish a cultivation system of Sedum sarmentosum using a rice nursery tray ($30{\times}60{\times}3\;cm$) in non-heating plastic film house, cuttings of two local strains (Wanju and Keumsan) were prepared and planted at different planting densities (40, 60 and 80 cuttings per tray) on September 7th, and subsequent growth and yield at pre- and post-winter season were investigated. When pre-wintering growth were measured at 60 days after planting, high planting density (80 cuttings/tray) decreased leaf length and lateral shoot number per plant compared to 40 cuttings/tray. When post-wintering growth were measured on April 20th, no significant growth differences as affected by planting density were observed in Keumsan strain, while decreased stem diameter, node number and leaf number were observed in Wanju strain planted at 80 cuttings/tray compared to 40 cuttings/tray. Fresh and dry weights were not significantly different as affected by planting density, but those were significantly increased in Wanju strain compared to Keumsan strain. When regrowth characteristics followed by the first harvest were measured on June 5th, significantly increased stem number was observed at 80 cuttings/tray compared to 40 cuttings/ tray. Fresh and dry weight were significantly increased in Keumsan strain planted at 80 cuttings/tray compared to 40 cuttings/tray, and dry weight were increased in Wanju strain compared to Keumsan strain. Wanju strain showed higher shoot yield, thicker stem, shorter node and larger leaf, and non-succulent stem under high planting density compared to Keumsan strain. Accordingly, the optimum density was 40 cuttings per tray, and Wanju strain was adequate for the cultivation system using a rice nursery tray.

• Journal of Bio-Environment Control
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• v.10 no.2
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• pp.111-117
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• 2001

This experiment was conducted to elucidate the effects of foliar application of monopotassium phosphate on the acceleration of ind color and fruit quality of Satsuma mandarin cultivated in the plastic greenhouse. The 'a'value of peel chromaticity increased seasonably with the increasing frequency of foliar application of monopotassium phosphate, but became gradually irresponsive as the fruit approached to harvesting time. Glucose content increased with the number of foliar applications so did the fructose content. Content of reducing sugars tended to increase with the number of foliar applications by 0.32 to 0.41%.mL$^{-1}$ juice in treatment sof ive or more applications. Sucrose content increased gradually with the increasing number of foliar applications, but there was no significatn difference among treatments. Total sugar also increased with the increasing number of foliar applications Generally, the soluble solid level is considered to be representative of fruit quality. Sugar content increased with the number of foliar application up to 5 times in which sugar content increased by 0.93$^{\circ}$Bx as compared to the control. The fruit acidity of the treatment plots decreased as compared to that of the control, but there was no significant difference in fruit acidity among foliar application times.

• Horticultural Science & Technology
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• v.16 no.4
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• pp.533-536
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• 1998

In order to develop a pretreatment solution for cut rose, the effects of surfactants [Tween 20, Triton X-100, polyoxyethylene 4 lauryl ether (PLE)], germicides (aluminum sulfate, $AgNO_3$, dichloroisocyanuric acid, STS, benzalkonium chloride, 8-hydroxyquinoline sulfate), sucrose, and hormones (ABA and kinetin) on the longevity and quality of 'Red Sandra' were investigated in environment-controlled room. Although 20 and 50 ppm Tween 20, and 500 ppm PLE appeared, in appearance, to be effective in retarding blueing and wilting, respectively, they didn't show statistical differences as compared to distilled water control. Among germicides, $AgNO_3$ was the most effective in delaying petal blueing, petal withering, and reduction of fresh weight, regardless of its concentration, while, in the case of STS, only 1mM treatment was effective in delaying of petal withering. Only 5% sucrose treatment delayed petal blueing, petal withering, and bent neck, but showed no significant difference as compared to 500 ppm aluminum sulfate. Finally, single or combination treatments of ABA and cytokinin were found to rather stimulate the senescence of cut rose.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.2
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• pp.114-120
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• 2001

Ginkgo biloba L. has been planted in the city as street trees because reported as resistant species to air pollutant. Especially, the trees planted on the street of 'Cheongro', Mt. 'Nam', and 'Jamsil' have been exposed to air pollutant for a long time. This study was conducted to examine chlorophyll contents and genetic variation of Ginkgo biloba in the areas. Chlorophyll contents measured in the above three areas were variable although the the diameter at breast height measured in 'Cheongro' and Mt. 'Nam' were constant. In addition, the result showed positive relation between chlorophyll contents and DBH in this study. Eight enzyme systems were analyzed in megagametophytes which were collected in the areas and separated to two groups based on chlorophyll contents. All the enzymes appeared to be polymorphic : Got-2, Pgi-2, Pgm, Acon, Mnr, Mdh, Skdh, and 6Pgd. The sensitive (S) groups varied from 1.253 to 2.571 in the genetic diversity and the tolerant (T) groups ranged from 1.416 to 2.825. The observed single locus heterozygosities (H$_{0}$) ranged from 0.056 to 0.611 in the S groups, and from 0.179 to 1.643 in the T groups. The expected heterozygosities (H$_{e}$) ranged from 0.208 to 0.629 in the S groups and from 0.321 to 0.658 in the T groups. In addition, the H$_{0}$ values averaged over all loci were 0.326 for the T groups and 0.299 for the S group, respectively. A difference between the two groups was 0.027. The T groups had the unique alleles and genotypes and all the parameters for genetic diversity showed that the T groups had higher genetic diversity than the S groups.s. genetic diversity than the S groups.

• Journal of Life Science
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• v.27 no.7
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• pp.849-856
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• 2017

The ${\beta}$-D-fructofuranosidase (EC 3.2.1.26) is an important enzyme from a historical point of view, discovered by French biologist Berthelot in 1860 and was first used to study enzymology. ${\beta}$-D-fructosfuranosidase catalyzes the hydrolysis of sucrose into D-glucose and D-fructose. Four biochemical subgroups of ${\beta}$-D-fructofuranosidase have been investigated in plants. There are vacuolar (soluble acid), cytoplasmic (soluble alkaline), membrane-bound (insoluble alkaline), and cell wall-bound (insoluble acid) ${\beta}$-D-fructofuranosidase by purification. Their biochemical characteristics are distinct. It suggested that those enzymes might be different gene products. The contribution of each of these enzymes to sucrose management in the plant is likely to be correlated with their localization. Common localization in developing cells in tissues from a range of developmental stages and plant parts suggests that all of the isoforms may be closely involved in nutrient transport. The ${\beta}$-D-fructofuranosidases were most commonly found associated with maturing tissues in developing fruits, leaves, and roots. The ${\beta}$-D-fructofuranosidase activity varies in the relationship between growth and expansion through cell division, development of storage organs and tissues, and the relationship of plant defense responses. It is necessary to summarize more researches in order to know the definite physiological function.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.427-432
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• 1999

Changes in saponin composition and microstructure of ginseng by microwave vacuum drying were determined. Korean fresh ginsengs were subjected to four different processing : 3 min microwave vacuum drying and 2 min holding-24 hrs drying (MWVD1), 5 min microwave vacuum drying and 2.5 min holding-24 hrs drying (MWVD2), 3 min microwave vacuum drying and 2 min holding-12 hrs drying after hot air drying for 12 hrs drying at $45^{\circ}C$ (HMWVD1), 5 min microwave vacuum drying and 2.5 min holding-12 hrs drying after hot air drying for 12 hrs at $45^{\circ}C$ (HMWVD2). The water content was decreased until 16.82% without shrinkage and water activity was 0.54 after microwave vacuum drying. The lipid content was decreased after microwave vacuum drying (MVD). Glucose was increased after MVD while sucrose decreased. Ginsenoside-Rb1 and ginsenoside-Rc were decreased after MVD. Ginsenoside-Rg1 for MWVD2 and HMWVD2 was higher than that of MWVD1 AND HMWVD1. MWVD1 AND HMWVD1 dried ginsengs showed a more compact structure than the HMWVD2 and HMWVD2 ginsengs.