• Journal of Forest and Environmental Science
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• v.10 no.1
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• pp.57-65
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• 1994

This study was carried out to clarify the sediment export by measuring suspended solids included in streamflow during the rainy season. The study area is located in Experimental Forests, Kangwon National University, where the forest road is under construction. For this purpose, the forest watershed with construction of forest road was compared with normal forest watershed in amount of rainfall and discharge, suspended solids and discharge, and the amount of rainfall and suspended solids. The results were shown as followings. 1. The relationship of discharge and the amount of rainfall was shown as Table 3 and Fig. 3. The delay time of peak point observed in hydrograph was changed by rainfall intensity and amount of previous rainfall. That is, when there was a rain on 12. Jun(more than 20mm/hour for hours), the peak point began three hours after the rainfall intensity over 20mm/hour, and showed $1514m^3/hour$ in automatic water level recorder. In case of the 8th of Aug.(maximum rainfall intensity: 40mm/hour), the peak point of discharge was $1246m^3/hour$ in the same time with maximum rainfall intensity. And on the 20th of Aug.(the maximum rainfall intensity: 17.2mm/hour), the peak point of discharge was $1245m^3/hour$ two hours after the maximum rainfall intensity. 2. On watershed under forest road construction, the relationship between discharge and suspended solids is that suspended solids was proportionately increased by raising discharge. That is, on the 12th of Jun, the maximum of discharge per hour was $1514m^3/hour$ and 1261mg/l of suspended solids was observed an hour after peak point of discharge. And in case of 8th and 20th Aug., each of peak points is $1246m^3/hour$ and $1245m^3/hour$ by measuring time. The maximums of suspended solids measured within two watersheds were examined in value of 4952mg/l and 472mg/l at the same time. 3. During the rainy season, the concentration of suspended solids was influenced by rainfall intensity and indicated especially curve-regressional increase in case of strong rainfall intensity. In each of watersheds, the maximums of suspended solids were 1261mg/l and 125mg/l, 4952mg/l and 44mg/l, and 472mg/l and 4mg/l by the order of rain(a), (b), and (c). Two watersheds showed a remarkable difference.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1977.06a
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• pp.4.4-5
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• 1977

The vibratory energy introduced into the external ear canal is changed by the mechanical factors of eardrum itself, the motility of ossicles, and the air cushion of tympanic cavity and the like. This study was designed to investigate the volume of middle ear cavity and mastoid air cell system as a factor of determining the accoustic impedance of middle ear system. The author studied how the increase in air volume of middle ear cavity effects on the acoustic impedance of middle ear system with dogs' ears and researched the correlation between the degree of pneumatization of temporal bones and the acoustic impedance of middle ear system by comparing the radiological findings of pneumatization (Law's and Towne's projection) with the acoustic impedance measurements with Madsen ZO 70. The result is as follows: 1 The tympanometric findings in control state revealed the curves of type A, and did not change in its configuration by the increase in the air volume of dogs middle ear system. 2. The static compliance of middle ear revealed a distinct and linear increase in proportion to the increase in air volume of middle ear system; the rate of increase was $0.05{\pm}0.02$ cc of static compliance per cc of air volume. 3. Authenticated in the above result and the tendency to increase in static compliance in proportion to the increase in the degree of pneumatization of temporal bones, there was significant regression equation between the degree of pneumatization of temporal bones (x variable) and the static compliance of middle ear system; $y=0.19x{\pm}0.16{\pm}0.05$ It is suggested that the difference in volume of middle ear system plays an important role in the change of the static compliance of middle ear, and the author concludes that the measurement of static compliance of middle ear has clinical value as diagnostic means of evaluating the degree of pneumatization of temporal bones along with some radiological examination.

• Tuberculosis and Respiratory Diseases
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• v.44 no.3
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• pp.611-620
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• 1997

Objectives : The differentiation of tuberculous effusion from the other causes of exudative pleural effusion remained difficult even with aids of biochemical analyses and pleural biopsy. As the pathophysiology of tuberculous pleural effusion is an enhanced cell mediated immunity, Adenosine deaminase(ADA) and various eytokines including Inteferon-$\gamma$, tumor necrosis factor alpha(TNF-$\alpha$) are considered as useful diagnostic tools in differentiating exudative pleural effusion. The author would like to demonstrate the diagnostic usefulness of TNF-$\alpha$ in the differentiation of exudative pleural effusion, and compared the discriminating ability of TNF-$\alpha$ with ADA. Methods : Pleural fluids obtained from 80 patients (tuberculous : 39, malignant : 31, parapneumonic : 10) with exudate pleural effusions were processed for cell counts and biochemical analysis including ADA and TNF-$\alpha$. Results : Tuberculous pleural fluid showed higher levels of ADA and TNF-$\alpha$, $48.7{\pm}32.7U/L$ and $184.1{\pm}214.2pg/mL$ than that of non-tuberculous effusion $26.0{\pm}41.3U/L$ and $44.1{\pm}114.2pg/mL$, respectively (ADA, TNF-$\alpha$, p < 0.05, p < 0.01). Receiver operating characteristics(ROC) curves were generated for ADA and TNF-$\alpha$ and the best cut-off value for adenosine deaminase and TNF-$\alpha$were considered as 30U/L and 15pg/ml, respectively. Comparing the area under the ROC curves, there was no significant difference between ADA and TNF-$\alpha$. Conclusion : For the differential diagnosis of tuberculous pleural effusion from the other causes of exudative pleural effusions, TNF-$\alpha$ as well as ADA was considered as useful diagnostic method. However adding TNF-$\alpha$ to ADA has no further diagnotic benefit than ADA alone.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.1
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• pp.55-60
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• 2010

Purpose: The shrinkage of dental resin cement may cause several clinical problems such as distortion that may jeopardize the accurate fit to the prepared tooth and internal stress within the restorations. It is important to know the polymerization shrinkage-strain of dental resin cement to reduce clinical complications. The purpose of this study was to investigate the polymerization shrinkage-strain kinetics of six commercially available dental resin cements. Material and methods: Three self-cure resin cements (Fujicem, Superbond, M-bond) and three dual-cure resin cements (Maxcem, Panavia-F, Variolink II) were investigated. Time dependent polymerization shrinkage-strain kinetics of the materials were measured by the Bonded-disk method as a function of time at $23^{\circ}C$, with values particularly noted at 1, 5, 10, 30, 60, 120 min after mixing. Five recordings were taken for each materials. The data were analyzed with one-way ANOVA and Scheffe post hoc test at the significance level of 0.05. Results: Polymerization shrinkage-strain values were 3.72%, 4.19%, 4.13%, 2.44%, 7.57%, 2.90% for Fujicem, Maxcem, M bond, Panavia F, Superbond, Variolink II, respectively at 120 minutes after the start of mixing. Panavia F exhibited maximum polymerization shrinkage-strain values, but Superbond showed minimum polymerization shrinkage-strain values among the investigated materials (P < .05). There was no significant differences of shrinkage-strain value between Maxcem and M bond at 120 minutes after the start of mixing (P > .05). Most shrinkage of the resin cement materials investigated occurred in the first 30 minutes after the start of mixing. Conclusion: The onset of polymerization shrinkage of self-cure resin cements was slower than that of dual-cure resin cements after mixing, but the net shrinkage strain values of self-cure resin cements was higher than that of dual-cure resin cements at 120 minutes after mixing. Most shrinkage of the dental resin cements occurred in the first 30 minutes after mixing.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.22 no.1
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• pp.31-44
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• 2017

Pfiesteria piscicida is one of heterotrophic dinoflagellate having toxic metaboliges, and it is difficult to detect and quantify this dinoflagellate via light microscope due to small size and morphological similarity with Pfiesteria-like dinoflagellate (PLD) species. Alternatively, we developed quantitative real-time PCR assay based on EvaGreen and determined field accessibility throughout the investigation of distribution in the entire Korean coastal waters and population dynamics in Shihwa Lake. The P. piscicida-specific primers based on internal transcribed spacer 1 (ITS 1) were designed and the specificity of primers was confirmed by PCR with other genomic DNAs which have genetic similarity with target species. Through real-time PCR assay, a standard curve which had a significant linear correlation between log cell number and $C_T$ value ($r^2{\geq}0.999$) and one informative melting peak ($88^{\circ}C$) were obtained. These results implies that developed real-time PCR can accurately detect and quantify P. piscicida. Throughout the field applications of real-time PCR assay, P. piscicida was distributed in western (Mokpo and Kimje) and easthern (Gangneng) Korean coastal water even though light microscopy failed to identify P. piscicida. In the investigation of population dynamics in Shihwa Lake, the density of P. piscicida was peaked in June, July and August 2007 at St. 1 where salinity (${\leq}15psu$) was lower than the other 2 sites. In this study, we successed to develop EvaGreen bassed real-time PCR for detection and quantification of P. piscicida in fields, so this developed assay will be useful for various ecological studies in the future.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.4
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• pp.449-456
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• 2018

Cervical cancer is the fourth most frequently diagnosed cancer in women worldwide. In lower Human Development Index countries, it has the second highest incidence and mortality among cancer in women. Therefore, better diagnosis and treatment systems are needed. Among them, estrogen receptor alpha ($ER-{\alpha}$) mRNA expression has been analyzed with RT-qPCR since several studies reported that $ER-{\alpha}$ is necessary in the maturation of the uterus and is related to cervical cancer. In this study, $ER-{\alpha}$ quantitative analysis was performed on various lesions and normal tissue samples. Based on the receiver operating characteristic (ROC) curve, its sensitivity and specificity were 85% and 75%, respectively, showing higher or similar results to those of conventional HPV tests. In addition, its expression level was analyzed with clinical information. With regression analysis, the R square value between the $ER-{\alpha}$ mRNA expression level and menopause status was 0.5041, indicating a strong correlation. This study was performed as part of a pilot study and suggests that $ER-{\alpha}$ is related to carcinogenesis. Future studies will examine other hormones and menopausal factors with a larger sample size.

• New Physics: Sae Mulli
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• v.68 no.12
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• pp.1293-1301
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• 2018

The basic magnetic properties of commercially available High-$T_c$ Superconductor (HTS) GdBCO-coated conductor (GdBCO-CCs) were investigated by using physical property measurement system-vibrating sample magnetometer (PPMS-VSM). From the zero-field-cooled (ZFC) m(T) curve, the $T_c$ was found to be ~93 K. After removing the background m(H) data, we obtained both the net m(H) data and the ${\Delta}m_{irr}$. The $H_{irr}(T)$ coincided very well with the power-law relation $H_{irr}=H_{irr}(0)(1-T/T_c)^n$ with $$n{\sim_=}1.19$$. The magnetic flux behavior was investigated by using the ${\delta}$ values in the relationship $J_c{\propto}{\Delta}m_{irr}{\propto}H^{-{\delta}}$. A ${\delta}{\approx}0$ region denoting an independent magnetic flux pinning effect, a ${\delta}{\approx}0.6{\sim}1.2$ region representing a collective flux pinning effect due to the interaction, and a ${\delta}{\gg}2$ region representing freely moving magnetic fluxes caused by the Lorentz force were observed. The boundary line between ${\delta}{\approx}0$ and ${\delta}{\approx}0.6{\sim}1.2$ is denoted by a $H_1$, and the one between ${\delta}{\approx}0.6{\sim}1.2$ and ${\delta}{\gg}2$ is denoted by a $H_2$. The ${\delta}(T)$ was obtained in the region of $H_1$ < H < $H_2$. As the temperature was decreased, the ${\delta}$ value gradually decreased.

• Analytical Science and Technology
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• v.22 no.5
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• pp.432-438
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• 2009

In order to develop the analytical method for the pharmaceutical tablets containing ranitidine HCl by square wave voltammetry (SWV), $5.00{\times}10^{-5}M$ ranitidine HCl solutions prepared with phosphate buffers of various pH values were investigated by SWV. The well defined main peak due to the electrochemical reduction of $-NO_2$ in the structure of ranitidine moved towards the cathodic direction by -70 mV/pH as the pH values were increased indicating the involvement of hydrogen in its reduction. The calibration curve, the plot of peak currents (Ip) vs. concentrations of ranitidine HCl in the range between $1.00{\times}10^{-7}M$ and $1.00{\times}10^{-5}M$ showed linearity with slopes of $232,530{\mu}A/M$ (pH 6.14), $289,015{\mu}A/M$ (pH 7.07) and $232,843{\mu}A/M$ (pH 8.01). When one pharmaceutical tablet was simply dissolved in the phosphate buffer with a pH value of 6.14 and determined by standard addition method using SWV, the within-day precision study (n=4) resulted in the contents of ranitidine HCl as $171{\pm}2.1mg$ ($102{\pm}1.3%$ of the specified contents, RSD of 1.2%) in a tablet of Curan$^{(R)}$. The inter-day precision for 5 days was 1.1% of RSD. For Zantac$^{(R)}$ the within-day precision study (n=4) showed the contents of ranitidine HCl as $167{\pm}0.8mg$ ($99{\pm}0.5%$ of the specified contents, RSD of 0.5%) in a tablet and the inter-day precision for 5 days was 0.3% of RSD.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.15 no.3
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• pp.140-147
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• 2010

We investigated the effects of water temperature, salinity and irradiance on the growth of the harmful algae Chattonella ovata isolated from South Sea, Korea. C. ovata grew under all combinations of water temperatures and salinity, except for all the salinity conditions at the water temperature of $10^{\circ}C$, with the salinity of 7.5 psu and 10 psu at $15^{\circ}C$, and 7.5 psu at $20^{\circ}C$ and $30^{\circ}C$. The maximum specific growth rate was $0.62\;day^{-1}$ at the combination of $30^{\circ}C$ and 30 psu. The results of two-way ANOVA indicated that growth rate depended greatly on the water temperatures while not being affected by interactions with the salinity. This indicates that C. ovata is a stenothermal and euryhaline organism, preferring high water temperatures. C. ovata did not grow at irradiance ${\leq}30\;{\mu}mol$ photons $m^{-2}s^{-1}$. Photoinhibition did not occur at $800\;{\mu}mol$ photons $m^{-2}s^{-1}$, which was the maximum irradiance used in this study. The irradiance-growth curve was described as $\mu$ = 0.74(I-16.0)/(I+43.9) at $30^{\circ}C$ and 30 psu. The half-saturation light intensity ($K_s$) was $75.9\;{\mu}mol$ photons $m^{-2}s^{-1}$ and compensation photon flux density ($I_c$) was $16.0\;{\mu}mol$ photons $m^{-2}s^{-1}$, especially this value was comparatively lower than those of Skeletonema costatum and other flagellates previously reported. Therefore, our results indicate that C. ovata has advantageous physiological characteristics for interspecific competition at the embayment and coastal areas of Korea in summer.

• Journal of Marine Life Science
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• v.9 no.1
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• pp.9-21
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• 2024

Paralytic shellfish poisoning (PSP) including Saxitoxin (STX) is caused by harmful algae, and poisoning occurs when the contaminated seafood is consumed. The mouse bioassay (MBA), a standard test method for detecting PSP, is being sanctioned in many countries due to its low detection limit and the animal concerns. An alternative to the MBA is the Neuro-2a cell-based assay. This study aimed to establish various test conditions for Neuro-2a assay, including cell density, culture conditions, and STX treatment conditions, to suit the domestic laboratory environment. As a result, the initial cell density was set to 40,000 cells/well and the incubation time to 24 hours. Additionally, the concentration of Ouabain and Veratridine (O/V) was set to 500/50 μM, at which most cells died. In this study, we identified eight concentrations of STX, ranging from 368 to 47,056 fg/μl, which produced an S-shaped dose-response curve when treated with O/V. Through inter-laboratory variability comparison of the Neuro-2a assay, we established five Quality Control Criteria to verify the appropriateness of the experiments and six Data Criteria (Top and Bottom OD, EC₅₀, EC₂₀, Hill slop, and R² of graph) to determine the reliability of the experimental data. The Neuro-2a assay conducted under the established conditions showed an EC₅₀ value of approximately 1,800~3,500 fg/μl. The intra- & inter-lab variability comparison results showed that the coefficients of variation (CVs) for the Quality Control and Data values ranged from 1.98% to 29.15%, confirming the reproducibility of the experiments. This study presented Quality Control Criteria and Data Criteria to assess the appropriateness of the experiments and confirmed the excellent repeatability and reproducibility of the Neuro-2a assay. To apply the Neuro-2a assay as an alternative method for detecting PSP in domestic seafood, it is essential to establish a toxin extraction method from seafood and toxin quantification methods, and perform correlation analysis with MBA and instrumental analysis methods.