• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.7
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• pp.902-907
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• 2007

This study was carried out to find the effect of ${\gamma}$ -irradiation on the physical properties of alginic acid and ${\lambda}$-carrageenan solution. Alginic acid and ${\lambda}$-carrageenan aqueous solution were irradiated with $Co^{60}$ ${\gamma}$ -rays in dosages ranging from 3 to 100 kGy, and then the molecular weight, viscosity and color were measured. The molecular weight of alginic acid and ${\lambda}$-carrageenan solution were decreased as the ${\gamma}$ -irradiation dosage increased. In addition, the viscosity of irradiated alginic acid and ${\lambda}$-carrageenan solution were decreased depending upon the ${\gamma}$ -irradiation dosage, too. The high dosage irradiated alginic acid and ${\lambda}$-carrageenan solution's color were changed to yellow. These results suggest that low dosage of ${\gamma}$ -irradiation from 3 to 20 kGy is a very effective method for producing low-molecular alginic acid and ${\lambda}$-carrageenan.

• Journal of Korean Society of Forest Science
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• v.88 no.3
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• pp.352-363
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• 1999

It has been rare to obtain reliable information related to the size of forest land in North Korea. Several sources of forest statistics, ranging from the first map of forest distribution in Korean Peninsula produced in 1910 to official data reported by the North Korea Government in 1997, were gathered and analyzed to define the characteristics of forest cover changes over years. In addition, Landsat satellite data obtained from 1973 to 1993 were processed for the two study areas of the provinces of Pyungyang and Heasan, where the topography and land use pattern are significantly different each other. Using three sets of multitemporal Landsat imagery, land cover ma-ps were produced by computer classification. Although forest statistics reported before 1990 are somewhat inconsistent, they mere gradually decreasing over years. The estimates of 1991 satellite data and the recent statistics reported in 1998 shows very steep decline in forest lands as compared to the ones before 1990. The abrupt decrease of forest lands after 1990 was also found on the detailed analysis of Landsat data for the two study areas of Pyungyang and Heasan. The rapid decline of forest lands may have something to do with the poor economic situation of the country and the continuing natural disasters of severe flooding and drought. Unstocked forest, which was not classified into forest land, was a very distinct and pervasive land cover type that can be easily observed on satellite imagery. Since unstocked forest land in North Korea may be a critical factor for degrading environmental quality as well as for the continuing natural disasters, further analysis is necessary to define the exact extent and the physical characteristics of the cover type.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.453-457
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• 2016

This study investigates the hatching periods and hatchability of the eggs of Pochazia shantungensis at different collection times from 2011 to 2014, and the effect of temperature on the growth of P. shantungensis nymphs in an area of its outbreak. The hatchability of P. shantungensis eggs varies with their collection time; their hatchability in late November was higher than that in March of the next year, but no difference was observed in their hatching periods. The hatching periods of the eggs were 51.2, 31.3, 24.8, 19.4, 17.1, and 19.4 days at 15, 18, 21, 24, 27, and $30^{\circ}C$, respectively. The hatchability was above 70% at temperatures ranging from 18 to $27^{\circ}C$. The hatching time of the overwintered eggs in the Gurye region in Korea was reduced by 9 days from 2011 to 2014. The hatching rate was relatively higher when the average temperature in the winter season was relatively warmer. The dvelopmental periods of the first to fifth nymphs were 82.8, 58.0, 45.8, and 39.6 days at 18, 21, 24, and $27^{\circ}C$, respectively, at the relative humidity of 40~70%, and a photoperiod off 14 h light:10 h dark. The higher the temperature, the shorter the developmental period. At $30^{\circ}C$, all life stages after the fourth nymph died. Thus, the optimum growth temperature was estimated to be $27^{\circ}C$. For all life stages from the egg to the fourth nymph, the relationship between the temperature and developmental rate was expressed by the linear equation Y = 0.0015 X - 0.014. The lower developmental threshold was $9.3^{\circ}C$ and the effective cumulative temperature was 693.3 degree-days. The lower developmental threshold of approximately $3.8^{\circ}C$ was the lowest at the fourth nymph stage.

• Korean Journal of Ichthyology
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• v.18 no.1
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• pp.1-11
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• 2006

Genomic DNA isolated from two geographical populations of pond-smelt (Hypomesus nipponensis) was amplified for RAPD (randomly amplified polymorphic DNA) analysis. The populations were obtained from Chungju (CJ), in the inland area, and Dangjin (DJ), in the vicinity of the West Sea in Korea. Seven arbitrarily selected primers, OPB-06, OPB-10, OPB-13, OPB-17, OPC-09, OPC-17 and OPC-20, were used to generate the shared loci, polymorphic, and specific loci. Three hundred and eighty-three loci observed per primer were identified in the CJ population, and 287 were identified in the DJ population. Among them, 91 polymorphic loci or 23.8% were polymorphic in the CJ population, and 47 (16.4%) in the DJ population. The number of shared loci observed was 198 in the CJ population and 176 in the DJ population. Forty-four and 75 specific loci were detected in the CJ and DJ populations, respectively. Especially, 99 numbers of shared loci by the two populations, with an average of 14.1 per primer, were observed in the two pond-smelt populations. The average bandsharing value between the two geographical pond-smelt populations was $0.700{\pm}0.008$, ranging from 0.600 to 0.846. Compared separately, the bandsharing value of individuals within the CJ population was higher than that of the DJ population. The dendrogram obtained using the data from the seven primers indicated three genetic clusters: cluster 1, CJ 01, 02, 03, 04, 05, 06, 07, 08, 09, 10, and 11; cluster 2, DJ 01, 02, 03, 04, 05, 06, 07, 08, and 09; and cluster 3, DJ 10 and 11. The genetic distance between the two geographical populations ranged from 0.040 to 0.545. Thus, RAPD-PCR analysis revealed a significant genetic distance between the two pond-smelt populations.

• Tuberculosis and Respiratory Diseases
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• v.47 no.3
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• pp.304-310
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• 1999

Background: IFN-$\gamma$ plays an important role in host response to intracellular organisms such as mycobacterium. Human infection with mycobacterium leads to a wide variety of outcomes, ranging from asymptomatic infection to widespread and rapidly fatal disease. Recent reports suggest that alteration of the function of IFN-$\gamma$ caused by a defective IFN-$\gamma$ receptor gene can explain different host response to mycobacterium. In this study, we investigated the role of IFN-$\gamma$ in the development of chronic refractory tuberculosis. Methods: The LPS-induced TNF-$\alpha$ production with or without IFN-$\gamma$ priming was compared by using monocytes taken from recently diagnosed tuberculosis, chronic refractory tuberculosis patients and controls. And the IFN-$\gamma$ receptor was measured by indirect fluorescent antibody technique to know whether change in the priming effect of IFN-$\gamma$ is related to IFN-$\gamma$ receptor deficiency or not. Results: The ratio of TNF-$\alpha$ produced in response to stimulation with INF-$\gamma$ and LPS to LPS alone was $13.5{\pm}7.6$ in controls, $10.8{\pm}6.4$ in recently diagnosed tuberculosis patients and $6.7{\pm}3.9$ in chronic refractory tuberculosis patients. The priming effect of IFN-$\gamma$ significantly decreased in chronic refractory tuberculosis patients compared with that in controls(p=0.002). However, IFN-$\gamma$ receptor deficiency was detected in one of chronic refractory tuberculosis patients. Conclusion: The decrease of the priming effect of IFN-$\gamma$ may play an important role in the development of chronic refractory tuberculosis, and in some patients, this may be related to the IFN-$\gamma$ receptor deficiency.

• Tuberculosis and Respiratory Diseases
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• v.47 no.3
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• pp.347-355
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• 1999

Background: Phospholipase C(PLC) plays a central role in cellular signal transduction and is important in cellular growth, differentiation and transformation. There are currently ten known mammalian isozymes of PLC reported to this date. Hydrolysis of phosphatidylinositol 4,5-bisphosphate($PIP_2$) by PLC produces two important second messengers, inositol 1,4,5-trisphosphate($IP_3$) and diacylglycerol. PLC-${\gamma}1$, previously, was known to be activated mainly through growth factor receptor tyrosine kinase. Other mechanisms of activating PLC-yl have been reported such as activation through tau protein in the presence of arachidonic acid in bovine brain and activation by $IP_3$, phosphatidic acid, etc. Very recently, another PLC-${\gamma}1$ activator protein such as tau has been found in bovine lung tissue, which now is considered to be AHNAK protein. But there has been no report concerning AHNAK and its associated disease to this date. In this study, we examined the expression of the PLC-${\gamma}1$ activator, AHNAK, in lung cancer specimens and their paired normal. Methods: From surgically resected human lung cancer tissues taken from twenty-eight patients and their paired normal counterparts, we evaluated expression level of AHNAK protein using immunoblot analysis of total tissue extract Immunohistochemical stain was performed with primary antibody against AHNAK protein. Results: Twenty-two among twenty-eight lung cancer tissues showed overexpression of AHNAK protein (eight of fourteen squamous cell lung cancers, all of fourteen adenocarcinomas). The resulting bands were multiple ranging from 70 to 200 kDa in molecular weight and each band was indistinct and formed a smear, reflecting mobility shift mainly due to proteolysis during extraction process. On immunohistochemistry, lung cancer tissues showed a very heavy, dense staining with anti-AHNAK protein antibody as compared to the surrounding normal lung tissue, coresponding well with the results of the western blot Conclusion: The overexpression of PLC-${\gamma}1$ activator protein, AHNAK in lung cancer may provide evidence that the AHNAK protein and PLC-${\gamma}1$ act in concerted manner in carcinogenesis.

• Tuberculosis and Respiratory Diseases
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• v.47 no.6
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• pp.807-816
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• 1999

Background: Sarcoidosis, uncommon in Korea, has variable clinical course, ranging from benign self-limited recovery to life-long disability regardless of corticosteroid therapy. The purpose of this study is to observe the clinical course of untreated sarcoidosis. Methods: Twenty four patients who were confirmed as sarcoidosis by tissue diagnosis were included. For average 12month follow-up periods, subjective symptoms, radiologic findings, and parameters of pulmonary function test(FVC, $FEV_1$, DLco) were evaluated every 3mooths compared between corticosteroid treated(n=5) and non-treated(n=19) patients. 'Deterioration' was defined if patients met more than one of followings (1) decrement in any parameters of pulmonary function test(2) worsening in the degree of dyspnea(3) increase in radiologic extents, and (4) newly developed extrapulmonary sarcoidosis. 'Stable' was defined as no significant interval changes in every parameters. 'Improvement' was defined as decrement of extension of the radiologic lesions without deterioration. Results: Among 19 untreated sarcoidosis patient, one deteriorated, 14 improved(13 of them showed complete resolution in radiology), and 4 were remained stable. On the other hand, five corticosteroid treated patients, uveitis was developed in one, 2 improved, and 2 remained stable. Conclusion : These findings suggest that patient with sarcoidosis, especially those without serious extrapulmonary disease, has stable clinical course and would not need corticosteroid therapy.

• Journal of Korean Society of Forest Science
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• v.85 no.1
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• pp.76-83
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• 1996

Four natural Quercus stands in Kwangju, Kyonggi-Do, of which ages ranging from 32 to 38 years old, were studied to compare their growth, biomass and net production. Ten $10m{\times}10m$ quadrats were set up and ten sample trees were harvested for dimension analysis in each stand. The largest mean DBH and height were shown by Q. acutissima stand, and followed by Q. variabilis stand, Q. mongolica stand, and Q. dentata stand in descending order. Tree density was the highest at Q. variabilis stand, and followed by Q. dentata stand, Q. mongolica stand, and Q. acutissima stand in descending order. Biomass was the largest at Q. acutissima stand(122.73t/ha), and followed by Q. variabilis stand(87.03t/ha), Q. mongolica stand(72.14t/ha), and Q. dentata stand(38.56t/ha) in descending order. Net production was the greatest at Q. mongolica stand(7.49t/ha/yr.), and followed by Q. variabilis stand(6.47t/ha/yr.), Q. acutissima stand(6.06t/ha/yr.), and Q. dentata stand(3.52t/ha/yr.) in descending order. The highest net assimilation ratio was exhibited by Q. acutissima stand (3.275), and followed by Q. variabilis stand(2.898), Q. mongolica stand(2.888), and Q. dentata stand (1.840) in descending order. The difference in net assimilation ratio and net production among four stands was caused by differences in their leaf biomass. The difference in net production and biomass among four stands was due to that in the distribution of net production among stems, branches and leaves.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.357-361
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• 2008

In this study, the antioxidant properties and physical characteristics of irradiated Sargassum siliquastrum water extract were evaluated. Samples were irradiated with $Co^{60}{\gamma}$-ray at doses ranging from 3 to 20 kGy. They were then analyzed to investigate antioxidant properties, including total phenolic compound content and DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity. In addition, physical properties such as viscosity and color were evaluated. The results demonstrated that total phenolic compound content and DPPH radical scavenging activity were significantly improved (p<0.05) by irradiation. In terms of physical properties, viscosity and color were reduced in the irradiated extracts as compared to non-irradiated samples. In conclusion, gamma irradiation improved the antioxidant properties of Sargassum siliquastrum water extract, improving its original weak point as a natural antioxidant when applied in the food industry.

• Journal of the Korean Geotechnical Society
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• v.15 no.2
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• pp.153-164
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• 1999

The solubilization of BTEX was evaluated in aqueous surfactant solutions with and without several additives. Anionic surfactant(Sodium Dodecyl Sulfate, SDS) and nonionic surfactants (NEODOL(equation omitted)25-3 and $SOFTANOL\circledR-90$ were used as test surfactants. The effects of surfactant HLB(Hydrophile-Lipophile Balance) Number and hydrocarbon molar volume and polarity of BTEX on the MSR(Molar Solubilization Ratio), micelle-water partition coefficient of BTEX, and CMC(C,itical Micelle Concentration) were investigated. Optimizing treatment conditions applicable to enhanced solubilization was also studied by manupulating salinity or electrolyte control with additives of ethyl alcohol, hydrotrope, and electrolyte solution. The most effective surfactant for solubilization was found $SOFTANOL\circledR-90$, since HLB number of 13.6 is similar to those values of BTEX ranging between 11.4 and 12.2, which was also proved experimentally. Ethyl alchohol of 3% was the most effective additives in reducing CMC and improving solubilization among the conditions using SDS, NEODOL(equation omitted)25-3, and $SOFTANOL\circledR-90$ with three additives. The partitioning of BTEX between surfactant micelles and aqueous solutions was characterized by a mole fraction micelle-phase/aqueous phase partion coefficient, $K_m$. Values of log $K_m$. for BTEX compounds in surfactant solutions of this study range from 2.95 to 3.76(100mM SDS) and 2.95 to 3.49(117mM $SOFTANOL\circledR-90$. Log $K_m$ appears to be a linear function of log $K_{ow}$ for SDS and $SOFTANOL\circledR-90$. A knowledge of partitioning of BTEX in aqueous surfactant system can be a prerequisite for the understanding of the behavior of hydrophobic organic compounds in soil-water systems in which surfactants play a role in remediation of contaminated soil and facilitated transport.