• The Journal of the Petrological Society of Korea
• /
• v.13 no.2
• /
• pp.103-118
• /
• 2004

In Cheongsong area, very rare spherulitic rhyolites both in Korea and foreign countries occur as dykes showing various types. The spherulites in them represent an undercooling caused by very fast cooling of the dykes in a shallow depth near to the surface and the variety of types were resulted from the difference of relative cooling rate. Cheongsong spherulitic rhyolites can be classified into five types; radiated simple spherulite, layered simple spherulite, layered multiple spherulite, radiated-layered multiple spherulite, radiating layered multiple spherulite. Radiated simple and radiating layered multiple spherulites formed by diffusion current caused by undercooling related to very fast cooling. On the other hand, layered multiple spherulites formed by relatively slow diffusion as a Liesegang ring during relatively slow cooling. If the cooling rate is between the two cases, layered simple spherulites formed. This interpretation indicates that Chrysanthemum, Dandelion, Dahlia and Sunflower types which are included in radiated simple or radiating layered multiple spherulites formed in the dykes with the fastest cooling rate in Cheongsong area while Peony, Rose and Innominate types classified as layered multiple spherulite formed in the dykes with the relatively slowest cooling rate. At the cooling rate between them, Apricot type spherulite formed. The K-Ar age-dating for Cheongsong spherulitic rhyolites indicate them to be formed between 48 and 50 Ma. The Cheongsong rhyolites are very valuable for research and preservation because of their rarity, beauty and diversity.

• The Korean Journal of Food And Nutrition
• /
• v.34 no.2
• /
• pp.233-241
• /
• 2021

The purpose of this study was to investigate the contents of apigenin and luteolin in vegetables mainly distributed and consumed in Korea. In this study, the contents of apigenin, apigenin-7-O-glucoside, luteolin, and luteolin-7-O-glucoside in vegetables were surveyed by using liquid chromatography coupled to mass spectrometry (LC-MS/MS). According to the analysis of 27 items (91 samples) in vegetables, the content of total apigenin (the sum of apigenin and apigenin-7-O-glucoside) was quantified in 8 out of the 27 items in vegetables, followed by pepper leaves, parsley, celery, chamnamul, foremost mugwort, and perilla leaves. The content of total luteolin (the sum of luteolin and luteolin-7-O-glucoside) was found in 11 of the 27 items in vegetables, followed by pepper leaves, dandelion, celery, red lettuce, foremost mugwort, and perilla leaves. Celery was divided into stalks and leaves for comparing the contents of apigenin and luteolin. Celery showed higher contents of apigenin and luteolin in leaves than in stalks.

• Journal of Rhinology
• /
• v.25 no.2
• /
• pp.91-98
• /
• 2018

Background and Objectives: The present study evaluated the results of skin prick test using 55 allergens at 20 centers in the Republic of Korea in 2006, 2010, and 2014-2015. The aim was to assess changes in the positive rate of allergens according to temporal, regional, and environmental factors. Materials and Method: In total, 20 hospitals were selected based on the population distribution in the Republic of Korea. A skin prick test panel comprising 55 aeroallergens was distributed to 18 hospitals for this prospective study. The 2006 and 2010 skin prick test results were collected and analyzed retrospectively from 20 hospitals, while the 2014/2015 skin prick test results (from June 2014 to May 2015) were collected prospectively from 18 hospitals. Results: A total of 14,897 SPT test results were analyzed: 4,319 in 2006, 7,431 in 2010, and 1,852 in 2014/2015. The overall rate of skin prick test positivity to more than two allergens was significantly higher in males than females. The positive rates of alder pollens and birch, oak and ragweed pollen positivity were increased in older patients. Several positive rates were increased according to the temperature in spring. The positive rates for beech pollen, birch pollen, hazel pollen, oak pollen, Tyrophagus putrescentiae, mugwort, cat, Acarus siro, Lepidoglyphus destructor and Tyrophagus putrescentiae were significantly increased, while those of Cult rye pollen and dandelion were significantly decreased over the three test periods. The overall positive rate for allergens in Jeju province varied significantly from Seoul and other cities. Conclusion: Change in the positive rate of multiple aeroallergens was evaluated in the Republic of Korea over time. Our findings can be used to recommend aeroallergens suitable for inclusion in skin prick test panels in the Republic of Korea and will facilitate further investigation of changes in the patterns of allergic diseases.