• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.5
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• pp.273-288
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• 1991

To elucidate the physiological and biochemical differences between chondrichthyes and osteichthyes, the properties of the specific digestive enzymes in cat-shark, Cephaloscyllium umbratile, and mackerel, Scomber japonicus, were studied. Homogenous trypsin proved through the disc-electrophoresis, SDS-PAG electrophoresis and gel filtration was obtained from the pancreas of cat-shark by $50-70\%$ saturated ammonium sulphate fractionation, DEAE-Sephadex A-50 column chromatography, benzamidine-Sepharose 6B affinity chromatography and Sephadex G-75-120 gel filtration. Two types of trypsins were also obtained from the pyloric caeca of mackerel by $30-70\%$ saturated ammonium sulphate fractionation and the slightly modified procedure from the method adopted in the purification of cat-shark trypsin. The two trypsins, designated trypsin A and B, were proved their homogeneity by disc- and SDS-PAG electrophoresis and gel filtration. The molecular weights of the trypsins were estimated to be 31,700 for cat-shark trypsin, 30,000 for mackerel trypsin A and 29,000 for mackerel trypsin B by SDS-PAG electrophoresis, but those were estimated to be 21,500 for cat-shark trypsin, 23,700 for mackerel trypsin A and 21,500 for mackerel trypsin B by gel filtration. The trypsins exhibited their optimum conditions at pH 9.0 and on temperature ranged from $45^{\circ}C\;to\;50^{\circ}C$ for cat-shark, and at pH 8.0 and a temperature of $50^{\circ}C$ for mackerel trypsin A and B, respectively. The cat-shark trypsin was stable at pH 10.0 and the temperature below $10^{\circ}C$, whereas the mackerel trypsin A and B, were stable in the range over pH 7.0 to pH 9.0 below $10^{\circ}C$ and at pH 8.0 below $35^{\circ}C$, respectively. The mackerel trypsins were severely inhibited by some heavy metal ions such as $Ag^{2+},\;Cu^{2+}\;and\;Hg^{2+}$ compared to cat-shark trypsin. All of the enzymes were also inhibited by antipain, leupeptin, TLCK(tosyllysine chloromethyl ketone) and SBTI(soybean trypsin inhibitor) remarkably. The inhibitory effects of PMSF(phenylmethane sulphonylfluoride), DFP(diisopropyl fluorophosphate) and benzamidine were indicated that these enzymes belong to serine-proteases.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.4
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• pp.539-549
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• 2012

In order to acquire basic data on the development of squid processing food, we investigated changes in the composition of boiled squid upon heat treatment ($100^{\circ}C$), acid treatment (acetic acid, 0~5%), and pre-boiling ($55^{\circ}C$, $80^{\circ}C$). The proximate composition of squid was 73~78% moisture and 19~24% crude protein, treatment with acid solution had a significant effect on the proximate composition of boiled squid (p<0.05). The major free sugars were ribose and glucose in all treatment samples. The $55^{\circ}C$ pre-boiled sample had lower levels of glucose than the other samples. The total free sugar content of the non-peeled sample was the highest, followed by the $80^{\circ}C$ pre-boiled sample, whereas the sugar content in the $55^{\circ}C$ pre-boiled sample was very low. With regards to amino acid content, proline was the highest in all samples, followed by taurine and histidine. Treatment with acid solution had a significant effect on the total free amino content of boiled squid (p<0.05). The total free amino acid content of the $55^{\circ}C$ pre-boiled sample was the highest, followed by the $80^{\circ}C$ pre-boiled sample and non-peeled sample. Inosine and related compounds were not detected in any of the samples, and the adenosine triphosphate (ATP) content was low. The hypoxanthine contents of the $55^{\circ}C$ and $80^{\circ}C$ pre-boiled samples were the highest, the adenosine monophosphate (AMP) and inosine monophosphate (IMP) contents were similar, and the IMP content of the non-peeled sample was higher than those of the peeled samples. The palmitic acid content was very high and constituted 40% of total saturated fatty acids. eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) contents were also high and constituted 60% of total unsaturated fatty acids. Of these, DHA content was the highest, followed by palmitic acid and EPA, which accounted for about 85% of total fatty acids. No difference in fatty acid content was observed between acid treatment and pre-boiling. The mineral P content was the highest on average in all boiled squid samples, followed by K, Na, Mg, and Ca contents. In addition, the pre-boiling temperature and acid solution concentration had significant effects on the mineral content. Further, heavy metal, Cd, Pb, and As contents were detected only at trace amounts, and their levels were lower than standard and permissible amounts for food.

• Korean Journal of Poultry Science
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• v.32 no.4
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• pp.245-254
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• 2005

This experiment was conducted to investigate the effect of the supplemental alkali feldspar-ilite(feldspar) on growth performance and meat quality in broiler ducks for 43 days. One hundred eighty broiler ducks were divided into 5 groups of 12ducks. Dietary levels of feldspar 0, 0+antibiotics, 0.5, 1.0 and $1.5\%$ were added to experimental diets of each of the groups. Daily weight gain was slightly increased in 1.0 and $1.5\%$ feldspar treatments. Feed intake was slightly increased at all feldspar treatments. Glucose concentration of serum profile was decreased whereas BUN concentration was significantly increased (p<0.05) at $0.5\%$ feldspar. Cholesterol concentration was decreased at all feldspar treatments, this difference was especially observed in supplemental levels of $0.5\%$ feldspar(p<0.05). Carcass weight was increased at all feldspar treatments. Moisture and crude fat contents of proximate chemical composition in duck meat were decreased at all feldspar treatment, this difference especially was observed in supplemental levels of $1.5\%$ feldspar(p<0.05) on crude fat content. Lightness and yellowness was increased at all feldspar treatment. Cholesterol contents and TBA in meat were decreased, but this parameters were not difference by feldspar treatment. The composition of saturated fatty acids(SFA) was decreased, whereas unsaturated fatty acids(USFA) was slightly increased by feldspar treatment. The Pb content of heavy metal concentrations was increased with compared control, but not difference. The appearance of sensory evaluation was improved by supplemental feldspar, especially in supplemental feldspar, 1.0 and $1.5\%$(p<0.05). The results of this study indicate that the supplemental alkali feldspar may improve the production and meat quality of broiler ducks.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.5
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• pp.333-343
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• 2003

This experiment was carried out to improve the utilization of liquid pig manure (LPM) for rice at the two textures of valley soil in 2000 and 2001. The soil textures were coarse loamy and fine loamy in Sachon and Jisan series, respectively. Treatments consisted of no fertilized plot, chemical fertilized plot, LPM 150%, LPM 100%, LPM 100%+NK (top dressing) 30%, LPM 70%+NK 30%, LPM 50%+NK 50% plot. LPM was applied as basal fertilizer compare to nitrogen of chemical fertilized plot. Total N contents in the LPM were 6.0 and $4.5g\;kg^{-1}$ in 2000 and 2001, respectively. After the experiment, P and K contents of soils were not difference between chemical and LPM application plots. But heavy metal contents in soils were slightly higher in LPM application plots than in chemical fertilized plot. Immediately after LPM application, ammonia gas content was $18mg\;kg^{-1}$ in LPM 150% plot, but it was $3mg\;kg^{-1}$ in LPM 50% plot. Two days after LPM application, ammonia gas content was 3 times higher in coarse loamy than in fine loamy soil. After rotary tillage, ammonia gas was not detected at all LPM treatments. This result suggests that rotary tillage can reduce the nasty smell of LPM quickly. Inorganic nitrogen, $NO_3$ and $NH_4$, contents in water of paddy was higher at coarse loamy soil from rice transplanting to tillering stage. After that season, inorganic nitrogen contents of water were not different according to soil texture and treatments. Content of $NH_4-N$ in soil solution was higher at LPM plots than chemical fertilizer plot. Total nitrogen contents in rice plant after harvesting were higher at chemical fertilization plot than LPM application plot, but K contents showed an opposite tendency. Rice yield was decreased only in LPM plots at two soil textures. But yield was not significantly difference between chemical fertilizer and LPM+top dressing plots at coarse loamy soil and increased 5% at LPM 50%+NK 50% plot at fine loamy soil in 2001.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.1
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• pp.1-7
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• 2001

Total upland area for cultivating the vegetable crops in the Alpine soils of Northeastern South Korea has been extending its limit to meet the increasing demand of vegetable food in recent decades. About 70% of these alpine soils are located in over 7% of the slope and most of vegetable crops have been cultivated intensively without practicing the best management systems. Thus, soil erosion and continuous cropping system have degenerated the soil fertility and shown detrimental effects on water quality. We initiated an intensive and extensive investigation to characterize the fertility problems encountered in these uplands. Objectives of this paper were to characterize the fertility status in the Alpine soils cultivated with vegetable crops for many years and to provide the recommendations for adequate soil management measures including fertilization and erosion control. Soils in general have good drainage with textural classes of loam or sandy loam. Their topographical characteristics tended to lead them to shallow plow layers, and the steepness of the terrain created erosion hazard. Of the soils examined, about 11% of uplands over 30% gradient was found in need of an urgent reforestation. A high content of gravel and firm hardness of soil attributed to inhibit the utilization of farm machinery and plant-root development. The average soil pH 5.6 was slightly low relative to pH 5.70 of the national average. Organic matter content was high compared with 2.0% of national average, but decreased with the prolonged cultivation periods. Available $P_2O_5$ concentration was unusually high due to the consequence of over dose application with chemical and organic fertilizers. Exchangeable cations as Ca, Mg, and K were appeared to be decreased in these regions with prolonging the cultivation periods. There were no significant differences in cation exchange capacity (CEC) and electrical conductivity (EC) among locations. Heavy metal contents were mostly lower than the threshold of danger level designated by Soil Environment Conservation Law of South Korea. Results indicated that a proper countermeasure and the best management practice should be immediately implemented to conserve the top soil and fertility in the Alpine regions.

• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.320-329
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• 2023

Cadmium (Cd), a heavy metal found in the aquatic environment, accumulates in organisms through the food chain. In the study, we investigated the survival rates, measurement of body Cd levels, and expression analysis of the stress response genes (Heat shock protein 70: HSP70 and Heat shock protein 60: HSP60) and antioxidant enzyme Glutathione S-Transferases (GST) on benthic oligochaete worm Tubifex tubifex exposed three concentrations of Cd, to analyze the bioaccumulation and changes of stress gene expressions to exposure toxicity of the Cd-spiked sediment. Survival rates of T. tubifex exposed to the Cdspiked sediment were 93% at 0.4 mg kg^-1 Cd, 96% at 1.87 mg kg^-1 Cd, and 93% at 6.09 mg kg^-1 Cd for 10 days. Cd concentration in the body of T. tubifex was higher than that in the sediment. After Cd exposures for 10 days, the body Cd levels were 18.4 mg kg^-1, 13.06 mg kg^-1, and 79.11 mg kg^-1 at exposed three concentrations of Cd, respectively. Upregulation of HSP70 gene expression was observed at all concentrations of exposed Cd as a time-dependent manner, whereas transcriptional expression of the HSP60 gene increased as a timedependent manner in T. tubifex exposed to the relative high concentration (6.09 mg kg^-1) of Cd. However, GST gene expression increased on day 1 at all concentrations after Cd exposures, and then downregulated until 10 days. These results indicate to ecotoxicological and molecular effects in benthic oligochaete worm T. tubifex to Cd-spiked sediment and provide the basic information for the utilization of environmental toxicity assessment using the T. tubifex as a aquatic pollution indicator species.

• Journal of Radiation Protection and Research
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• v.15 no.2
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• pp.27-39
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• 1990

Appreciable radiation exposures certainly were occurred in the reactor burn-up, the nuelear fall-out and the surroundings of nuclear installations with radioactive effluents. Therefore, radioactive nuclides is not only potentially hazardous to workers of nuclear power plants and related industrials, but also the wokers who handle radioactive nuclides in biochemical research and nuclear medicine diagnostics. And in the case of occurring the nuclear accidents, the early medical treatment of radiation injury should be necessary but little is established medical procedures to decontaminate the victims of internal contamination of radioactive nuclides in korea. Accordingly, to achieve the basic data for protective roles and medical treatment of radiation injury, the present studies were carrid out to evaluate the decontamination of uranium by the chemical drugs. The results observed were summarized as follows: 1. The combined treatmet group of sodium bicarbonate and saline with uranyl nitrate injection simultaneously and the dithiothreitol group that was administered 30 minutes after uranyl nitrate injection were increased significantly in the change of body weight than uranyl nitrate-only group (P<0.005). 2. All the experimental groups were increased the fluid intake and urine volume on the uranyl nitrate-induced acute renal failure. but the combined treatment group of sodium bicarbonate and saline with uranyl nitrate injection simultaneously and the dithiothreitol group that was administered 30 minutes after uranyl nitrate injection have the higher increment of fluid intake and urine volume (P<0.05). 3. When sodium bicarbonate and saline was treated with uranyl nitrate injection simultaneously. and dithiothreitol was administered 30 minutes after uranyl nitrate injection. there was significantly reduced in BUN concentration (P<0.01). 4. When dithiothreitol was administered 30 minutes after uranyl nitrate injection. there was reduced more significantly on the increment of serum creatinine concentration than that observed in uranyl nitrate-only group(P<0.01). but when the combined treatment of sodium bicarbonate and saline with uranyl nitrate simultaneously, there was still. albeit much less marked. decrease in serum creatinine concentration. 5. The sodium bicarbonate and saline was treated with uranyl nitrate simultaneously and dithiothreitol was administered at 30 minutes after uranyl nitrate were excreted markedly higher urine creatinine concentration than the uranyl nitrate-only group. 6. Uranyl nitrate has been used in experimental animals to produce hydropic degeneration and swelling of proximal tubules, disappearance of microvilli and brush border or necrosis in the kidney and centrilobular necrosis, congestion, and telangiectasia of the liver. When the sodium bicarbonate and saline was treated with uranyl nitrate simultaneously, and dithiothreitol was administered. 30 minutes after uranyl nitrate, there was more marked the protective effect than uranyl nitrate-only group. Finally, if the sodium bicarbonate and saline may administered as quickly as possible each time that some risk for internal contamination, with uranium, and dithiothreitol is administered 30 minutes after uranium contamination, there ameliorates the course of uranyl nitrate-induced acute renal failure.and this effect is assocciated with prevention of uranium (heavy metal)-induced alterations in BUN, serum creatinine, urine creatinine, fluid intake, urine volume and body weight.