• Journal of the Korean Society of Fisheries and Ocean Technology
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• 제21권2호
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• pp.131-136
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• 1985

The calculation of the resulting fluid motion is an important problem of ship hydrodynamics. For a partially immersed body the condition of constant pressure at the free surface can be linearized. The resulting linear boundary-value problem for the velocity potential is the Neumann-Kelvin problem. The two-dimensional Neumann-Kelvin problem is studied for the half-immersed circular cylinder by Ursell. Maruo introduced a slender body approach to simplify the Neumann-Kelvin problem in such a way that the integral equation which determines the singularity distribution over the hull surface can be solved by a marching procedure of step by step integration starting at bow. In the present pater for the two-dimensional Neumann-Kelvin problem, it has been suggested that any solution of the problem must have singularities in the corners between the body surface and free surface. There can be infinitely many solutions depending on the singularities in the coroners.

• Restorative Dentistry and Endodontics
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• 제31권5호
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• pp.344-351
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• 2006

The purpose of this study was to evaluate the thermal expansion characteristics of injectable ther-moplasticized gutta-perchas and a Resilon. The materials investigated are Obtura gutta-percha, Diadent gutta-percha, E&Q Gutta-percha Bar and Epiphany (Resilon). The temperature at the heating chamber orifice of an Obtura II syringe and the extruded gutta-percha from the tip of both 23- and 20-gauge needle was determined using a Digital thermometer. A cylindrical ceramic mold was fabricated for thermal expansion test, which was 27 mm long, with an internal bore diameter of 3 mm and an outer diameter of 10 mm. The mold was filled with each experimental material and barrel ends were closed with two ceramic plunger. The samples in ceramic molds were heated in a dilatometer over the temperature range from $25^{\circ}C$ to $75^{\circ}C$. From the change of specimen length as a function of temperature, the coefficients of thermal expansion were deter-mined. There was no statistical difference between four materials in the thermal expansion in the range from $35^{\circ}C$ to $55^{\circ}C$ (p > 0.05). However, Obtura Gutta-percha showed smaller thermal expansion than Diadent and Metadent ones from $35^{\circ}C$ to $75^{\circ}C$ (p < 0.05). The thermal expansion of Epiphany was similar to those of the other gutta-percha groups.

• Clinical and Experimental Pediatrics
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• 제51권3호
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• pp.315-322
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• 2008

Purpose : Prader-Willi syndrome (PWS) is a complex genetic disorder, caused by the deletion of the paternally derived 15q11-13 region or the maternal uniparental disomy of chromosome 15 (mUPD(15)). In this study, we compared phenotypic differences between those patients whose disease was caused by microdeletion and those caused by mUPD(15). In addition, a comparison of the efficacy of growth hormone (GH) therapy between these two PWS genotypes was analyzed. Methods : Fifty-three patients were diagnosed as having PWS based on molecular and cytogenetic analyses and clinical features. Data that included maternal age, birth weight, a feeding problem in the neonatal period, cryptorchidism, developmental delay or mental retardation, short stature, hypopigmentation, changes in height, weight, and body mass indexes (BMI) before and after GH treatment were obtained by a retrospective review of medical records. The data from the patients with microdeletion were compared with those from the patients with mUPD(15). Results : Of the 53 patients with genetically confirmed PWS, 39 cases had microdeletion and 14 mUPD(15). Maternal ages were significantly higher in the mUPD(15) group, and hypopigmentation and a feeding problem in the neonatal period were more frequent in the microdeletion group. Growth hormone was administered to 20 patients [14 with microdeletion, 6 with mUPD(15)]. There were no differences between the two groups in height velocity, weight and height SDS, and BMI after GH therapy. Conclusion : Phenotype and genotype correlations were observed in Korean PWS patients, such as more advanced maternal ages in the mUPD(15) group and more feeding problems and hypopigmentations in the microdeletion group. Further long-term prospective studies are needed to correlate other aspects of the phenotypes.

• The Korean Journal of Malacology
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• 제24권2호
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• pp.153-159
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• 2008

We investigated artificial mass seed production of a Chinese scallop, Patinopecten yessoensis, in 2004. The GSI(gonad somatic index) of the Chinese scallop, P yessoensis was 17.2 on mid-February, 20.2 on mid-March, while that of Korean scallop, P yessoensis was 6.9 on mid-February, 10.8 on mid-March. Matured 120 females and 350 males were selected for artificial mass production. They were exposed in air for 1 hr at over $20^{\circ}C$, and placed into a spawning tank(20 ton) containing sea water treated with UV radiation at $12^{\circ}C$. We gained a total of 228,000 thousand scallop embryos between March 10th and 15th, and reared larvae at the indoor tank during 25 days. When the mean shell length of larvae reached 250 ${\mu}m$ and they have eye-spots, the number of pre-settling larvae was 47,500 thousand. We gained 1,850 thousand attached scallop spats from two kinds of collectors. Attached spats were reared in indoor tank for different periods from 5 days to 60 days. They were divided into 5 groups according to the length of reared days. Each group of attached spats was moved to intermediate rearing sites at Yangyang fishing port in Gangreung-city for acclimation to ocean environments. The highest survival rate of attached spats was 13.0% shown at the group reared for 12 days, but the significant difference in their growth was not found between the groups. The shell length of artificial attached spats increased from 0.9 ${\mu}m$ on July 10th to 24.7 ${\mu}m$ on December 16th with the survival rate of 85.0% while that of natural attached spats increased from 0.6 ${\mu}m$ on July 10th to 23.9 ${\mu}m$ on December 16th with the survival rate of 85.7%.

• Molecules and Cells
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• 제21권1호
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• pp.52-62
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• 2006

In previous reports we demonstrated that ginsenosides, active ingredients of Panax ginseng, affect some subsets of voltage-dependent $Ca^{2+}$ channels in neuronal cells expressed in Xenopus laevis oocytes. However, the major component(s) of ginseng that affect cloned $Ca^{2+}$ channel subtypes such as ${\alpha}_{1C}$(L)-, ${\alpha}_{1B}$(N)-, ${\alpha}_{1A}$(P/Q)-, ${\alpha}_{1E}$(R)- and ${\alpha}_{1G}$(T) have not been identified. Here, we used the two-microelectrode voltage clamp technique to characterize the effects of ginsenosides and ginsenoside metabolites on $Ba^{2+}$ currents ($I_{Ba}$) in Xenopus oocytes expressing five different $Ca^{2+}$ channel subtypes. Exposure to ginseng total saponins (GTS) induced voltage-dependent, dose-dependent and reversible inhibition of the five channel subtypes, with particularly strong inhibition of the ${\alpha}_{1G}$-type. Of the various ginsenosides, $Rb_1$, Rc, Re, Rf, $Rg_1$, $Rg_3$, and $Rh_2$, ginsenoside $Rg_3$ also inhibited all five channel subtypes and ginsenoside $Rh_2$ had most effect on the ${\alpha}_{1C}$- and ${\alpha}_{1E}$-type $Ca^{2+}$ channels. Compound K (CK), a protopanaxadiol ginsenoside metabolite, strongly inhibited only the ${\alpha}_{1G}$-type of $Ca^{2+}$ channel, whereas M4, a protopanaxatriol ginsenoside metabolite, had almost no effect on any of the channels. $Rg_3$, $Rh_2$, and CK shifted the steady-state activation curves but not the inactivation curves in the depolarizing direction in the ${\alpha}_{1B}$- and ${\alpha}_{1A}$-types. These results reveal that $Rg_3$, $Rh_2$ and CK are the major inhibitors of $Ca^{2+}$ channels in Panax ginseng, and that they show some $Ca^{2+}$ channel selectivity.

• Journal of Mushroom
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• 제21권1호
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• pp.22-32
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• 2023

To investigate the effect of thinning intensity on environmental factors and ectomycorrhizal mushroom fruiting in forest ecosystems, we studied canopy closure, throughfall, soil temperature, soil moisture, light response of understory vegetation, and ectomycorrhizal mushroom fruiting in a 10-year-old pine forest after 34%, 45%, and 60% thinning. Canopy closure was significantly higher in the 34% treatment and control plots, ranging from 80-85% in April. However, in November, all thinning treatment plots showed a decrease of approximately 5-10% compared with the control plot. The 60% treatment plot had over 200 mm of additional throughfall compared with the control plot, and monthly throughfall was significantly higher by more than 100 mm in October. The soil temperature in each treatment plot increased significantly by up to 1℃ or more compared with the control plot as the thinning rate increased. The soil moisture increased by more than 5% in the thinning treatment plots during rainfall, particularly in the 34% treatment plot, where the rate of moisture decrease was slower. The photosynthetic rate of major tree species (excluding Pinus densiflora)was highest in Quercus mongolica, with a rate of 7 µmolCO₂·m^-2·s^-1. At a lightintensity of 800 μmol·m^-2·s^-1, Q. mongolica showed the highest photosynthetic level of 6 ± 0.3 μmolCO₂·m^-2·s^-1 in the 45% treatment. The photosynthetic rate of Fraxinus sieboldiana and Styrax japonicus increased as the thinning intensity increased. The Shannon-Wiener index of mycorrhizal mushrooms did not significantly differ among treatments, but the fresh weight of mushrooms was approximately 360-840 g higher in the 34% and 45% treatments than in the control. Additionally, the fresh weight of fungi in the 60% treatment was 860 g less than that in the control. There were more individuals of Amanita citrina in the control than in the thinning treatment, while Suillus bovinus numbers increased by more than 10 times in the 34% thinning treatment compared with the control.

• Journal of the Korea Concrete Institute
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• 제25권3호
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• pp.339-345
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• 2013

This study is to derive from the required performances and the optimum mix proportion of the roof concrete placed in the in-ground LNG storage tank with a capacity of 200000 $m^3$, and propose the actual data for site concrete work. The concrete placing work without sliding and segregation in the fresh concrete condition is very important because the slope of domed roof is varied in the large range by its curvature. Also the control of hydration heat and the strength development at test ages are classified with massive section about 1.4 m thick and considered to the pre-stressing work and removal of air support after concrete placing work. Considering above condition, slump range is selected $100{\pm}25$ mm under the slope $20^{\circ}$ and $150{\pm}25$ mm over the slope $20^{\circ}$ s until 60 minutes of elapsed time. Also, the roof concrete is satisfied with compressive strength range including design strength at 91 days (30 MPa), pre-stressing work at 7 days (10 MPa), air support removal work at 21 days (14 MPa). Replacement ratio of limestone powder is determined by confined water ratio test and main design factors include water-cement ratio (W/C), sand-aggregate ratio and dosage of admixture. As test results, the optimum mix proportion of the roof concrete used low heat cement is as followings. 1) Replacement ratio of limestone powder 25% by confined water ratio test 2) Water-cement ratio 57.8% 3) Sand-aggregate ratio 42.0%. Also, test results for the adiabatic temperature rising test is satisfied with its criteria and shown the lower value compared to preceding storage tank (TK-13, 14). These required performances and the optimum mix proportion is to apply the actual construction work.

• Journal of Korea Soil Environment Society
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• 제3권2호
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• pp.13-29
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• 1998

Recently, It is increasing popularity to research on the soil remediation in aspect of management by reason of the hazardous impact on the contaminated soil in Korea. It was investigated high levels of arsenic salts in soil near abandoned five mines(Darak, Daduk, Jingok, Dalsung, Ilkwang) located in Youngnam area. Arsenic, classified as group A(Human Carcinogens) from IRIS, have shown statistically significant increment in skin cancer with oral exposure. This paper was conducted to predict excess cancer risk value (to the skin cancer) based on multiple pathway such as soil ingestion, dermal uptake and food(plant) ingestion contaminated by arsenic, and also, to identify the remedial goal regarded in future land use. The mine having the highest arsenic level was Daduk(mean : 1950mg/kg) and the next rank was Jingok(1690mg/kg), Ilkwang(352.37mg/kg), Dalsung(86.08mg/kg), Darak(0.83mg/kg). The chronic daily intake to the multiple exposure were calculated using Monte-Carlo simulation regarded in future land use and used q: value was $1.5(mg/kg/day)^{-1}$ to the oral proposed by IRIS(1997). The computated excess cancer risk 95th value to all the mine regarding future land use as residential and rural area were more than $10^{-4}$. If the level of acceptable risk is aimed for 1$\times$$10^{-6}$, it could be used Darak as commercial and industrial area without soil remediation due to the lowest risk value(6$\times$$10^{-8}$ and 3$\times$$10^{-8}$). Computated remedial goal based on 1$\times$$10^{-6}$ of acceptable risk to the future land use as the residential, rural, commercial and industrial area were 0.02mg/kg, 0.003mg/kg, 97.31mg/kg and 194.62mg/kg, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제25권3호
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• pp.189-196
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• 1992

To know the extension effect of storage temperature on the pre-rigor period of plaice, Paratichthys olivaceus muscle, the relationship between early changes after death and temperature dependency was studied. Killed plaices instantly with spiking at the brain were stored at $-3^{\circ}C,\;0^{\circ}C,\;5^{\circ}C\;and\;10^{\circ}$ used in studying the changes in rigor Index, ATP and its related compounds, lactate contents and K-value. The most shortest onset time of rigor-mortis and full rigor was revealed in the sample stored at $-3^{\circ}C$ among the all samples, where rigor-mortis began at 4hrs after spiking and maximum tension was attained after 28hrs. However, in case of fresh plaice muscle stored at $10^{\circ}C$, the onset of rigor-mortis and full rigor were retarded to 14hrs and 52hrs after spiking. ATP in sample stored at $5^{\circ}C\;and\;10^{\circ}C$ were decomposed slowly than sample at $0^{\circ}C\;-3^{\circ}C $ and within 35hrs storage. The fastest rate and the maximum content of lactate accumulation were showed in sample stored at $-3^{\circ}$ among the all samples. The correlation coefficient(r) between the rate of rigor mortis and ATP breakdown, rigor mortis and lactate accumulation, and ATP breakdown and lactate accumulation were -0.981946, 0.965044, and -0.964728, respectively. Freshness of $-3^{\circ}C$ stored samples was maintained for the longest time compared with other stored samples. The times reached around $20\%$ of K-value were 240hrs for samples stored at $-3^{\circ}C,\;96hrs\;for\;0^{\circ}C\;samples,\;71hrs\;for\;5^{\circ}C\;samples,\;and\;22hrs\;for\;10^{\circ}C$ samples. Samples stored at $-3^{\circ}C,\;and\;0^{\circ}C$ were showed higher temperature dependency on rate of rigor-mortis, ATP breakdown, and lactate accumulation than $5^{\circ}C\;and\;10^{\circ}C$ stored samples, but those samples have a lower temperature dependency on K-value.

• Journal of Yeungnam Medical Science
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• 제12권1호
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• pp.113-123
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• 1995

This study was intended to identify the neurotic traits related to sexual abuse in female high school students. The Neurosis Scale of Middlesex Hospital Questionnaire was conducted to 320 female high school students in Taegu, Korea from July 10 to July 17, 1994. The results were as follows: 1) The sexual abuse victim group showed significantly higher neurotic traits of Free floating anxiety (p<0.05), Phobic(p<0.01), Obsession(p<0.01), Somatic(p<0.05), Depression(p<0.01) than the control group. 2) The Neurotic traits of Somatic(p<0.01), Depression(p<0.01), Hysteric(p<0.01) were higher in the multiple-abused than the single-abused. 3) When the duration of being abused was concerned, subjects with more than 1 year duration had significantly higher neurotic traits of Obsession(p<0.05), Somatic(p<0.05), Depression(p<0.05) than subjects with less than 1 year duration. 4) The neurotic traits of Phobic, Somatic, Depression were significantly higher in the subjects with higher intensity of sexual abuse than with lower intensity. S) Among 68 victims, 31 girls(45%) were assaulted by strangers, 10(14%) were by relatives, 7(10.3%) were by siblings, 6(8.8%) were by neihbors. Among them, 34 girls(50%) bad counselling or psychotherapy and the people to whom they had sought for help were friends(23 girls; 68%), parents (7 girls; 11.7%) and mental health professonals (2 girls; 5.9%).