• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.6
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• pp.559-564
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• 2000

We studied to find out the effect of water temperature on the egg development of pearl oyster, Pincata fucata martensii and Pacific oyster, Crassostrea gigas. The optimum water temperatures for egg development were $20{\~}25^{\circ}C$ in P. fucata martensii and $15{\~}25^{\circ}C$ in C. gigas. The required time from fertilization to D-shaped lana was $41.7\;hours\;at\;20^{\circ}C$ and 27.5 hours at $25^{\circ}C$ in P. fucata martensii, and 35.3 hours at $15^{\circ}C$, 26.3 hours at $20^{\circ}C$ and 17.6 hours at$ 25^{\circ}C$ in C. gigas, respectively. The relationships between the water temperature ($WT:^{\circ}C$) and the required time (h: hour) from fertilization to each developmental stage were given as follows; P. fucata martensii Up to 8-cell $$1/h=0.0463WT-0.6945 (r^2=0.9702)$$ Up to morula $$1/h=0.0196WT-0.2184 (r^2=0.8118)$$ Up to trochophore $$1/h=0.0076WT-0.0802 (r^2=0.8756)$$ Up to D-shaped larva $$1/h=0.0031WT-0.0380 (r^2=0.9075)$$ C. gigas Up to 8-cell $$1/h=0.0210WT-0.1123 (r^2=0.9862)$$ Up to morula $$1/h=0.0143WT-0.1077 (r^2=0.9833)$$ Up to trochophore $$1/h=0.0052WT-0.0218 (r^2=0.9857)$$ Up to D-shaped lawn $$1/h=0.0029WT-0.0170 (r^2=0.9689)$$ Biological minimum temperature for egg development of P. fucata martensii and C. gigas was calculated as $$12.3^{\circ}C and 5.7{\circ}C$$, respectively.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.3
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• pp.185-193
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• 2020

There have been many studies on the calcination of oyster shells in the perspective of recycling of resources. The quicklime made by the calcination of oyster shells is used either as it is or after reacting with water to transform to liquid lime before being used. However, the liquid lime made from calcined oyster shells show slightly different properties from that of limestone. In this study, to compare these properties of oyster shell with those of limestone, the samples were calcined and reacted with water at various temperatures to transform to a liquid lime and filtered using 150 ㎛ sieves to calculate the transform rate to liquid lime. The calcined limestone was transformed to liquid lime at all temperatures, but calcined oyster shell did not show any transformation at 30℃ and 50℃ under the experimental conditions of this study, and rather increased the weight for the remaining after filtration due to the presence of Ca(OH)₂ produced by the reaction with water, Even at 90℃, the transformation rate of calcined oyster shell to liquid lime was lower than that of limestone. This difference in oyster shell can be explained partly by the preventing calcined one from reacting with water by conchiolin which is protein found in the prismatic and pearl layers of oyster shell. Conchiolin is also known to be stable and does not decompose even at high temperature. However, even the calcined chalk layer without conchiolin shows lower transformation rate than that of calcined limestone, probably due to the small amount of Na in oyster shell, which may cause additional reaction including eutectic melt during calcination process.

• Advances in Traditional Medicine
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• v.7 no.4
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• pp.441-443
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• 2007

A preliminary in vitro acid neutralizing capacity test of twelve traditional Ayurvedic antacids were performed in this study. Five traditional preparations of ash of conch shell, ash of oyster, ash of pearl, limestone, and ash of cowrie showed high acid neutralizing capacity similar to standard antacid combination of $Al(OH)_3\;and\;Mg(OH)_2$. Among these the ash of conch shell found the highest acid neutralizing capacity. The ash of tamarind and ash of Achyranthus aspera showed moderate acid neutralizing capacity. The acid neutralizing capacity of red ochre; ash of iron; mixture of niter, alum and ammonium chloride; saltpeter; and ash of mica found below the USP 23 limit.

• Journal of Aquaculture
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• v.9 no.4
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• pp.445-452
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• 1996

Endogeneous activities of ${\beta}-galactosidase$-like enzyme in various tissues from several finfishes and shellfishes were examined by histochemical analysis based on X-gal staining and by fluorimetric measurement using 4-methylumbelliferyl-${\beta}$-D-galactoside (4-MUG). Species used in this study were 3 freshwater fishes, mud loach (Misgurnus mizolepis), common carp (Cyprinus carpio) and tilapia (Oreochromis niloticus) ; 3 marine fishes, olive flounder (Paralichthys olivaceus), stone flounder (Kareius bicoloratus) and marbled sole (Limanda yokohamae) ; and 4 shellfishes, abalone (Haliotis discus hannai), Pacific oyster (Crassoskra gigas), pearl oyster (Pinctada fucata martensii) and ark shell (Anadara broughtonii). The activities of ${\beta}-galactosidase$-like enzyme in all finfishes examined were significantly different among species, with the wide variations between tissues in a species. In general, the tissues such as kidney, intestine and liver were ones which showed the significantly higher values in 4-MUG fluorimetry and deeper staining patterns in X-gal analysis compared to other tissues. On the other hand, serum and muscle revealed the significantly lower activities than others did, regardless of species. Shellfishes were also found to have endogenous activities of ${\beta}-galactosidase$-like enzyme which were significantly varied depending on both species and organs in a species. Hepatopancreas from all shellfishes examined showed the deepest pattern in X-gal staining and also the highest value in 4-MUG analysis, while activities of ${\beta}-galactosidase$-like enzyme in adductor muscles and mantle muscles from all shellfish species in this study except Pacific oyster were negligible : Pacific oyster had the significant activity of this enzyme in muscle tissues. Putative endogenous lacZ fragment was amplified from both finfishes and shellfishes by polymerase chain reaction (PCR). The molecular size of PCR products was about 510 bp, and there was no difference in size among species examined.

• Journal of Mushroom
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• v.17 no.4
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• pp.224-229
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• 2019

The two most common mushroom species grown in Korea are pearl oyster mushroom (Pleurotus ostreatus) and king oyster mushroom (P. eryngii). In recent years, the production of king oyster mushroom greatly increased due to the automation of the cultivation facilities, and it became a major export mushroom owing to its excellent shelf life. However, the increase in the production of king oyster mushroom led to a decline in its market price; thus, necessitating the development of new mushroom species that could replace king oyster mushroom, to diversify the mushroom market for the benefit of both, the producers and the consumers. The Mushroom division at the National Institute of Horticultural & Herbal Science (NIHHS) reported the development of a new interspecific hybrid between P. ferulae and P. tuoliensis, referred to as 'Creamy.' Two parental strains KMCC00430 (Bisan2ho, P. ferulae) and KMCC00461 (P. tuoliensis) were selected based on the results of genetic resource analysis, and their monokaryons were collected. About 1,000 Mon-Mon crosses were performed and 73 of them were selected. Following repeated cultivation tests and strain analyses, we selected strain 7773, which had a bright creamy pileus and a thick straight stipe, and named it 'Creamy.' Optimum temperature for mycelial growth of Creamy was 25-30℃, and that for fruiting body growth was 16℃. The pileus, which had a brighter creamy color, was small in size with a diameter of 61.2 mm. Although it was cultivated in suboptimal conditions, such as low temperature and high CO₂ concentration, Creamy was characterized by its straight and smooth stipe. Field production tests and further analyses indicated that the yield of Creamy was 5% higher than that of Baekhwang. It is expected that Creamy, the new interspecific hybrid with a bright creamy pileus and a pleasant flavor, will help create new opportunities for mushroom farmers and diversify the mushroom market.

• The Korean Journal of Food And Nutrition
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• v.25 no.1
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• pp.90-98
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• 2012

With the addition of ethanol to wax gourd extract and by acetic fermentation, 5.0% acidity vinegar was produced. After putting 10% extract(10% concentration) of Chrysanthemum zawadskii in this, and by dissolving shell, Chrysanthemum zawadskii-pearl vinegar was produced. When a 1% of ark shell, oyster shell, or ear shell was added to wax gourd vinegar, 95.6~98.4% of the shell dissolved, and when a 2% content of shell was added, 97.2~98.4% was dissolved. The acidity of vinegar which dissolved 1% shell was pH 3.0~3.17, and the acidity of vinegar which dissolved 2% shell was pH 1.11~ 1.20. The pH values of vinegar which dissolved 1%, and 2% shell contents were 4.54~4.55, and 4.86~4.95, respectively. When 1% shell was dissolved, the acidity was higher than that of commercial vinegar, with a high pH value and low level of free acid. This shows that when Chrysanthemum zawadskii 1% is added during acetic acid fermentation, the inhibition was 44.4%, and 22.2% respectively. In this regard, Chrysanthemum zawadskii should be added after the fermentation of acetic acid. The calcium content of 1% shell vinegar is 0.4%, and that of 2% vinegar is 0.78%. Non-heated native wax gourd shows an angiotensin converting enzyme inhibition rate of 21.7%, an antioxidant activity of 5.23%, and a tyrosinase inhibition rate of 5.5%. In the case of heated-extracted wax gourd, the angiotensin converting enzyme inhibition rate was 16.1%, superoxide dismutase activity was 20.5%, antioxidant activity was 23.2%, and the tyrosinase inhibition rate was 7.1%. Also, in the case of Chrysanthemum zawadskii, the angiotensin converting enzyme inhibition rate was 28.8%, the xanthine oxidase inhibition rate was 28.2%, the superoxide dismutase activity was 14.5%, the antioxidant activity was 3.2%, and the tyrosinase inhibition rate was 9.2% Data also revealed that when a 10% sample of the heated-wax gourd extract was added to A549 human lung cancer epithelial cells of, the number of cancer cells declined by 80% in 72 hours, When a 10% native extract was added, the number of cells declined by, 74% in 48 hours, and when a heated-extract of Chrysanthemum zawadskii was added, 100% of the cells died after 72 hours.