• Preventive Nutrition and Food Science
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• v.18 no.1
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• pp.18-22
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• 2013

To investigate radical scavenging effects and protective activities of bitter melon (Momordica charantia) against oxidative stress, in vitro and a cellular system using LLC-$PK_1$ renal epithelial cells were used in this study. The butanol (BuOH) fraction of bitter melon scavenged 63.4% and 87.1% of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals at concentrations of 250 and $500{\mu}g/mL$, respectively. In addition, the BuOH fraction of bitter melon effectively scavenged hydroxyl radicals (${\cdot}OH$). At all concentrations tested, the scavenging activity of the BuOH fraction was more potent than that of the positive control, ascorbic acid. Furthermore, under the LLC-$PK_1$ cellular model, the cells showed a decline in viability and an increase in lipid peroxidation through oxidative stress induced by pyrogallol, a generator of superoxide anion ($O_2{^-}$). However, the BuOH fraction of bitter melon significantly and dose-dependently inhibited cytotoxicity. In addition, 3-morpholinosydnonimine (SIN-1), a generator of peroxynitrite ($ONOO^-$) formed by simultaneous releases of nitric oxide and $O_2{^-}$, caused cytotoxicity in the LLC-$PK_1$ cells while the BuOH fraction of bitter melon ameliorated oxidative damage induced by $ONOO^-$. These results indicate that BuOH fraction of bitter melon has protective activities against oxidative damage induced by free radicals.

• Mycobiology
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• v.46 no.2
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• pp.154-158
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• 2018

Bitter rot caused by the fungal genus Colletotrichum is a well-known, common disease of apple and causes significant yield loss. In 2013, six fungal strains were isolated from Fuji apple fruits exhibiting symptoms of bitter rot from Andong, Korea. These strains were identified as Colletotrichum fructicola and C. siamense based on morphological characteristics and multilocus sequence analysis of the internal transcribed spacer rDNA, actin, calmodulin, chitin synthase, and glyceraldehyde-3-phosphate dehydrogenase Pathogenicity tests confirmed the involvement of C. fructicola and C. siamense in the development of disease symptoms on apple fruits. This is the first report of C. fructicola and C. siamense causing bitter rot on apple fruit in Korea.

• Korean Journal of Human Ecology
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• v.9 no.2
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• pp.215-221
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• 2000

Pueraria Radix has known to contain several ingredients of medical action. However, the bitter taste of Pueraria Radix has been an obstacle to develope the products and improve the added value of Pueraria Radix. To moderate the bitter taste of extracts from Pueraria Radix, charcoal powder was used successfully as an adsorbent. The component of the bitter taste from Pueraria Radix was hydrophobic, which mostly eluted with 40-60% ethanol and estimated to be acidic. Puerarin, the essential medical ingredient remained after the adsorption and seemed not be affected by the adsorption to charcoal powder.

• Journal of Practical Agriculture & Fisheries Research
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• v.6 no.1
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• pp.73-80
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• 2004

This study was conducted to determine the effect of several kinds of calcium foliar application and drip irrigation on the bitter pit incidence of apple. CaCl₂, inorganic calcium compound, was the most effective in increasing the calcium concentration in the fruit flesh, and reducing bitter pit incidence. Calcium spray in the later part of the growing season was more effective than in the earlier part. Drip irrigation applied during the dry spells increased calcium concentration in the fruit flesh, and reduced bitter pit incidence.

• The Plant Pathology Journal
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• v.34 no.6
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• pp.480-489
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• 2018

Bitter rot caused by Colletotrichum species is a common fruit rotting disease of apple and one of the economically important disease in worldwide. In 2015 and 2016, distinct symptoms of bitter rot disease were observed in apple orchards in five regions of South Korea. In the present study, infected apples from these regions were utilized to obtain eighteen isolates of Colletotrichum spp. These isolates were identified and characterized according to their morphological characteristics and nucleotide sequence data of internal transcribed spacer regions and glyceraldehyde-3-phosphate-dehydrogenase. Molecular analyses suggested that the isolates of Colletotrichum causing the bitter rot disease in South Korea belong to 4 species: C. siamense; C. fructicola; C. fioriniae and C. nymphaeae. C. siamense and C. fructicola belonged to Musae Clade of C. gloeosporioides complex species while C. fioriniae and C. nymphaeae belonged to the Clade 3 and Clade 2 of C. acutatum complex species, respectively. Additionally, we also found that the isolates of C. gloeosporioides species-complex were more aggressive than those in the C. acutatum species complex via pathogenicity tests. Taken together, our results suggest that accurate identification of Colletotrichum spp. within each species complex is required for management of bitter rot disease on apple fruit in South Korea.

• Molecules and Cells
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• v.43 no.6
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• pp.530-538
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• 2020

The Gustatory system enables animals to detect toxic bitter chemicals, which is critical for insects to survive food induced toxicity. Cucurbitacin is widely present in plants such as cucumber and gourds that acts as an anti-herbivore chemical and an insecticide. Cucurbitacin has a harmful effect on insect larvae as well. Although various beneficial effects of cucurbitacin such as alleviating hyperglycemia have also been documented, it is not clear what kinds of molecular sensors are required to detect cucurbitacin in nature. Cucurbitacin B, a major bitter component of bitter melon, was applied to induce action potentials from sensilla of a mouth part of the fly, labellum. Here we identify that only Gr33a is required for activating bitter-sensing gustatory receptor neurons by cucurbitacin B among available 26 Grs, 23 Irs, 11 Trp mutants, and 26 Gr-RNAi lines. We further investigated the difference between control and Gr33a mutant by analyzing binary food choice assay. We also measured toxic effect of Cucurbitacin B over 0.01 mM range. Our findings uncover the molecular sensor of cucurbitacin B in Drosophila melanogaster. We propose that the discarded shell of Cucurbitaceae can be developed to make a new insecticide.

• Progress in Superconductivity and Cryogenics
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• v.5 no.1
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• pp.1-12
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• 2003

In this paper we present a brief description and summary results of each of our recent activities in three areas, all devoted to NMR and MRI superconducting magnet technologies: 1) development of a high-field LTS / HTS NMR magnet; 2) development of a novel digital flux injector for slightly resistive NMR magnets; and 3) a proposal fer a low-cost MRI magnet system based on $MgB_2$ composite and an innovative cryogenic design / operation concept.

• Journal of the Korean Magnetics Society
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• v.10 no.3
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• pp.143-148
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• 2000

We made MnZn ferrites by conventional ceramic processing method and observed magnetic domain structures by Bitter method. The Bitter method revealed that the domain structure of the surface is stripe-like. When a magnetic field was applied, the domain wall motion was observed during the initial magnetization process and the irregular motion of domain wall or domain rotation was observed near the saturation magnetic field (90∼120 Oe).

• Superconductivity and Cryogenics
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• v.11 no.2
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• pp.23-29
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• 2009

The unique features of HTS offer opportunities and challenges to a number of applications. In this paper we focus on NMR and MRI magnets, illustrating them with the NMR/MRI magnets that we are currently and will shortly be engaged: a 1.3 GHz NMR magnet, an "annulus" magnet, and an $MgB_2$whole-body MRI magnet. The opportunities with HTS include: 1) high fields (e.g., 1.3 GHz magnet); 2) compactness (annulus magnet); and 3) enhanced stability despite liquid-helium-free operation ($MgB_2$whole-body MRI magnet). The challenges include: 1) a large screening current field detrimental to spatial field homogeneity (e.g., 1.3 GHz magnet); 2) uniformity of critical current density (annulus magnet); and 3) superconducting joints ($MgB_2$magnet).

• Journal of the Korean Home Economics Association
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• v.32 no.1
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• pp.133-150
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• 1994

This study was a survey of the taste for color arrangement and the relation to taste with food color. The term of investigation and object was the same as before mentions. The data-treatment was determinded by frequence percentage chi-square and F-test as measured by SAS program for PC and statistical figures were obtained by GDAS. The results were as follows;1. In the taste of arrangement for food, color. The most frequent colors were green and white followed by a yellowish green red. In preference 50's object was difference from another aged. It's significance was showed orange yellow pink and white. 2. In the relation of food color and taste term the color shown a pungent sweet hot and delicious taste was red and a sour astringent sweet taste was orange and anastringent bitter delicate hard taste was brown and a proteiny sofe sweet delicate taste was yellow and a cool taste was yellow and a cool taste was green, and a cool, bitter taste was blue and an astrngent taste was pink, and a bitter hard, tasteeless taste was black and a proteiny sofe taste was white. But in the case of any a bitter taste it's significance was shown.