• Korean Journal of Food Science and Technology
• /
• v.34 no.1
• /
• pp.18-23
• /
• 2002

The detection characteristics of gamma-irradiated $(0{\sim}4\;kGy)$ soybeans produced in Korea and China were investigated by thermoluminescene (TL), electron spin resonance (ESR), and DNA comet assay. The TL glow curves were shown at around $200^{\circ}C$ for irradiated soybeans, while that at $280^{\circ}C$ for the non-irradiated one. The normalization with a re-irradiation step at 1 kGy could verify the above detection results. The Korean soybean showed higher glow curves than Chinese did. The ESR spectroscopy for husks of irradiated soybeans revealed specific signals (g = 2.02374, 1.98715) derived from cellulose radical, which intensities were proportional to irradiation does, with the higher peaks in Chinese sample than Korean one. The DNA comet for the non-irradiated sample showed no or little tails, while those for irradiated samples above 0.5 kGy were remarkably changed in their length, size, and concentration, thus resulting in distinguishing non-irradiated from irradiated samples. As a result, TL, ESR, and DNA comet determinations were found suitable for the detection of irradiated soybean at 0.5 kGy or more, and negligible differences were observed between Korean and Chinese origins in their detection characteristics.

• Journal of Environmental Science International
• /
• v.17 no.8
• /
• pp.891-898
• /
• 2008

This study was conducted to develop the effects of site environmental factors on estimation of site index function for Chamaecyparis obtusa Endlicher stands. We derived nonlinear growth equation and the draw site index curves by applying this estimated equation. This study with Chapman-Richards function showed significant P-value which was less then 0.0001 and $R^2$ value 0.5947. This study was conducted to develop the feasible site index equation of Chamaecyparis obtusa Endlicher. For the table, the data of 82 sample areas that were thought to be without errors among the data of Chamaecyparis obtusa Endlicher sample area located on the value-oriented forest location chart were used and estimated. After analyzing the quantification method I based on 13 environmental factors to develop the score table for the site-index estimation of Chamaecyparis obtusa Endlicher, $R^2$ value of the model was 0.7555. It has been analyzed that the scope value of Soil moisture in horizon A was 7.5045, that of total soil depth was 6.3896, that of topography was 5.3471, that of slope was 4.7000 and that of aspect was 3.2038. After analyzing the partial correlation to examine the factors that affected most the site-index of Chamaecyparis obtusa Endlicher, it has been noted that the partial correlation of climatic zone was 0.4987, which was highest, and it was followed by Soil moisture in horizon A (0.4592), slope (0.4537), topography (0.3299) and total soil depth (0.1035). As a result of conducting the significance test for partial correlation, it has been found that topography, climatic zone, parent rock, slope, altitude, aspect, Soil moisture in horizon A, soil hardness in horizon A and total soil depth were recognized significant with 1% of significance level and sedimentary type and soil texture in horizon A were recognized significant with 5% of significance level.

• Restorative Dentistry and Endodontics
• /
• v.12 no.1
• /
• pp.39-49
• /
• 1986

The purpose of this study was to observe characteristic properties through the polarization curves and SEM images from 4 different types of amalgam obtained by using the potentiostats (Princeton EG & G) & SEM (Jeol/35), and to investigate the degree of corrosion on the oxidation peak of the each phase of amalgam. After each amalgam alloy and Hg was triturated as the direction of the manufacturer by means of the mechanical amalgamator (Shofu Co.), the triturated mass was inserted into the cylindrical metal mold which was 12mm in diameter and 10.0mm in height and was condensed by using routine manner. The specimen was removed from the mold and stored at room temperature for about 24 hours. The standard surface preparation was routinely carried out. Anodic polarization measurement was employed to confirm the corrosion behaviour of the amalgams in a 0.9% saline solution (P.H: 6.8-7.0) at $37^{\circ}C$. The initial rest potential (corrosion potential) was determined after 30 minutes of immersion of specimen in electrolyte, and the potential scan was begun at the point of 100mV cathodic from the corrosion potential. The scan rate was 0.17mV/sec. in the study to observe the degree of corrosion of each phase. SEI and EPMA images on the determined oxidation peaks of each amalgam were observed. The results were as follows: 1. In the four anodic polarization curves, low copper amalgams have three oxidation peaks and high copper amalgams have two oxidation peaks, -270mV, +26mV and +179mV(SEC) in the low copper lathe cut, and -300mV, +39mV and +163mV(SEC) in the low copper spherical. -4mV and +154mV(SEC) in the Dispersalloy, and +17mV and +180mV(SEC) in the Tytin as high copper amalgams. 2. ${\gamma}_2$ phase in the low copper amalgam and ${\eta}$ phase in the high copper amalgam were the most corrodible phases and Ag-Cu eutectic in high copper amalgam was the most slowly corroded phase. 3. Low copper amalgam was more susceptible in corrosion than high copper amalgam.

• Journal of Gastric Cancer
• /
• v.8 no.4
• /
• pp.189-197
• /
• 2008

Purpose: Peritoneal lavage cytology is regarded as a useful diagnostic test for detecting intraperitoneal micrometastsis. However, there are currently no reports about cytological examination with $ThinPrep^{(R)}$ (CY), a newly introduced fluid-based diagnostic system, in patients with advanced gastric cancer (AGC). This study was performed to analyze the clinical significance of intraoperative peritoneal lavage for CY in AGC patients. Materials and Methods: 424 AGC patients were suspected to have serosal exposure macroscopically during surgery and they underwent intraoperative peritoneal lavage for CY between 2001 and 2006 at Korea Cancer Center Hospital. The clinical data, pathological data and CY results were collected and analyzed retrospectively. Results: The percentage of cytology positive results was 31.1%, and this was well correlated with the T-stage, N-stage and P-stage. The 3-year survival rates of CY0 and CY1 were 68.1% and 25.9%, respectively. According to the P-stage and CY, the 3-year survival rates were 71.1% in P0CY0, 38.9% in P0CY1, 38.5% in P1/2/3CY0 and 11.0% in P1/2/3CY1. Interestingly, both the P0CY1 and P1/2/3CY0 survival curves were similar figures, but they were significantly different from those of the other groups. Multivariate analysis indicated that CY was an independent, strong prognostic factor for survival, as well as sex, the T-stage, N-stage, P-stage, other metastasis and the serum CEA. CY1 was revealed as a risk factor for peritoneal recurrence in the curative resection group. Conclusion: The results certify indirectly that cytological examination using $ThinPrep^{(R)}$ is a very reliable diagnostic method for detecting intraperitoneal micrometastasis from the fact that it is not only a strong prognostic factor, but it is also a risk factor for peritoneal recurrence in AGC patients. Therefore intraoperative peritoneal lavage should be included in the routine intraoperative staging workup for AGC, and its result will provide a good target for the treatment of peritoneal micrometastasis.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.17
• /
• pp.7529-7534
• /
• 2015

Background: The epidermal growth factor (EGF) plays important roles in non-small cell lung cancer (NSCLC) susceptibility and functional polymorphism in the EGF (+61A/G) gene has been linked to increased risk of NSCLC. This study aimed to evaluate the role of the EGF +61A/G polymorphism in risk of NSCLC adenocarcinoma (ADC) occurrence and survival in an Indian population. Materials and Methods: This casecontrol study included 100 histopathologically confirmed NSCLC (ADC) patients and 100 healthy controls. EGF (A61G) was genotyped by AS-PCR to elucidate putative associations with clinical outcomes. The association of the polymorphism with the survival of NSCLC patients was estimated by Kaplan-Meier curves. Results: It was found that EGF 61AG heterozygous and GG homozygous genotype is significantly associated with increased risk of NSCLC (ADC) occurrence compared to AA genotype, [OR 2.61 (1.31-5.18) and 3.25 (1.31-8.06), RR 1.51(1.15-2.0) and 1.72 (1.08-2.73) and RD 23.2 (6.90-39.5) and 28.53(7.0-50.1) for heterozygous AG (p=0.005) and homozygous GG (p=0.009)]. Patients homozygous for the G allele exhibited a significantly poor overall survival. The median survival time for patients with EGF 61 AA, AG, and GG genotypes was 10.5, 7.4, and 7.1 months (p=0.02), respectively. NSCLC (ADC) patients with GG + AG exhibited 7.3 months median survival compared to the AA genotype (p=0.009). Conclusions: The present study revealed that the EGF A61G genotype may be a novel independent prognostic marker to identify patients at higher risk of occurrence and an unfavourable clinical outcome.

• Microbiology and Biotechnology Letters
• /
• v.39 no.1
• /
• pp.77-85
• /
• 2011

The antibacterial activities of silver nanoparticles (Ag-NPs) were studied with respect to Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli by observing the bacterial cells treated or not with Ag-NPs by FE-SEM as well as measuring the growth curves, formation of bactericidal ROS, protein leakage, and lactate dehydrogenase activity involved in the respiratory chain. Bacterial cells were treated with Ag-NPs powder, and the growth rates were investigated under varying concentrations of Ag-NPs, incubation times, incubation temperatures, and pHs. As a result, S. aureus and E. coli were shown to be substantially inhibited by Ag-NPs, and the antibacterial activity of Ag-NPs did not fluctuate with temperature or pH. These results suggest that Ag-NPs could be used as an effective antibacterial material.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.14 no.1
• /
• pp.22-29
• /
• 2000

This paper deals with the dielectric characteristics of $SF_6$ gas gap stressed by $\pm$1.2/44[$mutextrm{s}$] non-oscillating impulse and $\pm$0.4[$mutextrm{s}$]/1.14[MHz] oscillating impulse voltages in the presence of a needle-shape metallic particle in gas-insulated switchgear(GIS). Breakdown voltage-time (V-t) and breakdown voltage-gas pressure (V-p) characteristics were investigated and discussed. The experiments were carried out under highly inhomogeneous field geometry with a needle protrusion whose length and radius are 10[mm] and 0.5[mm], respectively. The gas pressure ranges from 0.1 to 0.5[㎫]. As a result, it was found that the electrical breakdown for both the positive and negative polarity develops with steplike pulses in leader mechanism, When subjected to the positive oscillating impulse voltage, the minimum breakdown voltages appeared in all the gas pressure ranges and the V-t curves have a pronounced upturning at short times to breakdown and give a little dependence of the gas pressure. On the other hand, in the case of the negative polarity the dependence of the V-t and V-p characteristics on the wave shape of the applied voltages is known to be appreciable.

• Journal of Radiation Protection and Research
• /
• v.22 no.2
• /
• pp.103-109
• /
• 1997

Adult male rats were exposed to a whole body with a single dose of 1.0, 2.0, 3.0, 5.0, and 7.0 Gy. The animals were sacrificed 48, 72, 96 and 216 hours following exposure. A competitive enzyme linked immunosorbent assay(ELISA) with antigen immobilized on the solid phase has been developed to measure ceruloplasmin in rat serum and complete dose response curves. Ceruloplasmin was purified from the plasma of turpentine treated male rats. Coating of ceruloplasmin had more effectiveness in 10 mM Tris-HCI, 150 mM sodium chloride, pH 7.4 than in 50 mM carbonate/bicarbonate buffer, pH 9.6. The coating range for ceruloplasmin was $70{\sim}140ng$/well. Levels of ceruloplasmin increased to maximum on the $72{\sim}96$ hours after irradiation. Slope of between response and dose was greatest value 96 hours following irradiation. Normal ceruloplasmin levels were not recorded 216 hours following exposure. In 0.1 Gy irradiated group, levels of ceruloplasmin also increased to maximum on the $72{\sim}96$ hours following irradiation. The concentration of this protein remained significantly different from control value, 196 hours after exposure. Ceruloplasmin was identified as one of the major acute phase protein following irradiation and further studies about gene expression and regulation would be necessary for radiation protection.

• Tuberculosis and Respiratory Diseases
• /
• v.79 no.4
• /
• pp.289-294
• /
• 2016

Background: The aim of our study was to evaluate the prognostic value of Charlson's weighted index of comorbidities (WIC) in patients with prolonged acute mechanical ventilation (PAMV, ventilator care ${\geq}96$ hours). Methods: We retrospectively enrolled 299 Korean PAMV patients who were admitted in a medical intensive care unit (ICU) of a university-affiliated tertiary care hospital between 2008 and 2013. Survivors were defined as patients who survived for 60 days after ICU admission. Results: The patients' mean age was $65.1{\pm}14.1$ years and 70.6% were male. The mean ICU and hospital length of stay was $21.9{\pm}19.7$ and $39.4{\pm}39.1$ days, respectively. In addition, the 60-day mortality rate after ICU admission was 35.5%. The mean WIC was $2.3{\pm}1.8$, with significant differences between nonsurvivors and survivors ($2.7{\pm}2.1$ vs. $2.1{\pm}1.7$, p<0.05). The area under the curve of receiver-operating-characteristics curve for WIC was 0.593 (95% confidence interval [CI], 0.523-0.661; p<0.05). Based on Kaplan-Meier curves of 60-day survival, WIC ${\geq}5$ had statistically lower survival than WIC <5 (logrank test, p<0.05). In a multivariate Cox proportional hazard model, WIC ${\geq}5$ was associated with poor prognosis (hazard ratio, 1.901; 95% CI, 1.140-3.171; p<0.05). The mortality rate of patients with WIC ${\geq}5$ was 54.2%. Conclusion: Our study showed a WIC score ${\geq}5$ might be helpful in predicting 60-day mortality in PAMV patients.

• The korean journal of orthodontics
• /
• v.28 no.1 s.66
• /
• pp.123-133
• /
• 1998

The effectiveness of TiN ion-plating was examined with TiN ion-plated Co-Cr wires(.016“, .016”x.022“) on three different types of bracket(TiN ion-plated metal bracket ceramic bracket and plastic bracket). Maximum static frictional forces and characteristic curves obtained from the frictional characteristic graph, were compared and surface roughness of wires and bracket slots before and after friction experiment was observed by SEM. The obtained results were as follows $\cdot$The frictional forces of TiN ion-plated wires were significantly lower than those of non ion-plated wires(p<0.05). $\cdot$On the effect of wire shape, the frictional forces of round wires were significantly lower than those of rectangular wires(p<0.05) $\cdot$As the result of the SEM observation on the wires and bracket slots after the friction experiment the surface of non ion-plated wires was rougher than that of TiN ion-plated ones. $\cdot$The difference between the static frictional forces and the kinetic frictional forces was not significant in case of the TiN ion-plated round ins, but the static frictional forces were a little higher than the kinetic frictional forces in the TiN ion-plated rectangular wires. $\cdot$The static frictional forces were much higher than the kinetic frictional forces in the case of non ion-plated wires.