• Journal of the Korean Electrochemical Society
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• v.10 no.4
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• pp.288-294
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• 2007

The LSCF cathode far Solid Oxide Fuel Cell was investigated to develop high performance unit cell at intermediate temperature by modified oxalate method with different electrolytes and different pH. The LSCF powders employed La, Sr, Co and Fe oxides, oxalic acid, ethanol and $NH_4OH$ solution were synthesized with pH controlled as 2, 6, 7, 8, 9 and 10 at $80^{\circ}C$ Single crystalline phase was obtained from pH $2{\sim}9$. on the other hand, $La_2O_3$ appeared from pH 10. Very fine powder with particle size of 50 nm was obtained at calcination temperature of $800^{\circ}C$ for 4 hours. LSCF cathode synthesized at pH 7 showed the highest electric conductivity in the temperature range of $600^{\circ}C$ to $900^{\circ}C$ its value was 950 S/cm at $900^{\circ}C$ Under same synthesis conditions, polarization resistance of each LSCF cathode was changed with different calcination temperatures. As-prepared powder presented 2.52, 1.54 and $2.58\;{\Omega}$ at $600^{\circ}C$ with ScSZ, 8Y-YSZ and GDC as its electrolyte respectively after calcination at $800^{\circ}C$ for 4 hours.

• Tuberculosis and Respiratory Diseases
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• v.45 no.6
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• pp.1277-1283
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• 1998

Background : Surgical tracheostomy(ST) is usually performed by surgeons in operating room. For a patient with mechanical ventilation, however, transportation to operating room for ST could be dangerous for patients. In addition, ST is often delayed due to unavailability of operating room or surgeon. Percutaneous dilatational tracheostomy(PDT), although novel in Korea, is gaining popularity as a bedside procedure in the hospitals of western countries. We evaluated the technical ease and safety of PDT in comparison with ST. Method : Thirty-eight patients in medical intensive care unit (ICU) who were either under mechanical ventilation for more than 7 days or required airway protection, were randomly assigned to ST(18 patients) or PDT(20 patients). Between two groups, there was no significant clinical difference except that female to male ratio was higher in the ST group. ST was performed by second year residents of the department of otolaryngology while PDT was performed by third grade medical resident and pulmonologist under bronchoscopic guide using Ciaglia Percutaneous Tracheostomy Set(Cook Critical Care, Bloomington, USA) in medical ICU. The following factors were compared between two groups : number of delayed cases after the decision for tracheostomy, procedural time, complications related to tracheostomy. Results : Delayed cases were 11 in ST group and 3 in PDT group (P<0.05). Procedural time was significantly shorter in PDT group ($15.6{\pm}7.1min$) than in ST group ($29.1{\pm}11.6min$, P<0.0001). Complications related to tracheostomy occurred in 5 cases in ST group : accidental decannulation (1), subcutaneous emphysema (2) and minor bleeding (2), and in 4 cases in PDT group : minor bleeding (2), subcutaneous emphysema (1) and premature extubation (1) (P>0.05). Conclusion : Since percutaneous dilatational tracheostomy was easy to practice and its complications were not different from surgical tracheostomy, PDT can be a useful bedside procedure for mechanically ventilated patients.

• Tuberculosis and Respiratory Diseases
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• v.67 no.3
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• pp.205-211
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• 2009

Background: Serum procalcitonin level has been considered prognostic during sepsis and septic shock. We investigated the significance of procalcitonin in critically ill patients with respiratory infections. Methods: The patients who had radiographically diagnosed diffuse lung infiltrations were enrolled on a prospective basis. Bronchoalveolar lavage (BAL) fluid for the purpose of quantitative cultures (${\geq}10^4$ cfu/mL) was obtained from all patients. Serum procalcitonin levels determined by PCT-Q kit were measured on BAL day and classified as follows; <0.5 ng/mL, 0.5~2.0 ng/mL, 2.0~10.0 ng/mL and >10.0 ng/mL. We analyzed the patient's characteristics according to outcome; favorable or unfavorable, defined as death. Results: Patients from the following categories were included: medical 17 (47.2%), surgical 9 (25%), and burned 10 (27.8%). APACHE II scores on admission to intensive care unit were 11.5${\pm}$6.89 and 11 (30.6%) had unfavorable outcomes. A procalcitonin level ${\geq}$0.5 ng/mL was in 17 (47.2%) of all. On univariate analysis, the frequencies of burn injury, mechanical ventilation, multiple organ failure, and a procalcitonin level ${\geq}$0.5 ng/mL were more often increased in patients with unfavorable outcomes than in those with favorable outcomes (p<.05). Also, a higher procalcitonin range and ventilator-associated pneumonia (VAP) were more closely associated with an unfavorable outcome (p<.05). However in multivariate analysis, a strong predictor of unfavorable outcome was burn injury (p<.05). A procalcitonin level ${\geq}$0.5 ng/mL was more sensitive in predicting VAP than unfavorable outcome. Conclusion: A higher procalcitonin level seems to be associated with VAP, but further study is required to know that procalcitonin would be a prognostic marker in critically ill patients with respiratory infections.

• Progress in Medical Physics
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• v.24 no.4
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• pp.295-302
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• 2013

We estimated secondary scattered and leakage doses for intensity-modulated radiotherapy (IMRT), volumetric arc therapy (VMAT) and tomotherapy (TOMO) in patients with liver cancer. Five liver patients were planned by IMRT, VMAT and TOMO. Secondary scatter (and leakage) dose and organ equivalent doses (OEDs) are measured and estimated at various points 20 to 80 cm from the iso-center by using radiophotoluminescence glass dosimeter (RPLGD). The secondary dose per Gy from IMRT, VMAT and TOMO for liver cancer, measured 20 to 80 cm from the iso-center, are 0.01~3.13, 0.03~2.34 and 0.04~1.29 cGy, respectively. The mean values of relative OED of secondary dose of VMAT and TOMO for five patients, which is normalized by IMRT, measured as 75.24% and 50.92% for thyroid, 75.14% and 40.61% for bowel, 72.30% and 47.77% for rectum, 76.21% and 49.93% for prostate. The secondary dose and OED from TOMO is relatively low to those from IMRT and VMAT. OED based estimation suggests that the secondary cancer risk from TOMO is less than or comparable to the risks from conventional IMRT and VMAT.

• Korean Journal of Poultry Science
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• v.45 no.4
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• pp.245-252
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• 2018

This study investigated the effect of LED light wavelength (color) on reproductive hormones and egg production of brown laying hens raised on floor. Red, blue, green and white colors of LED light were four treatments with four pens per treatment. One hundred forty four Hy-line brown laying hens (47 wks old) were allocated in a floor pen for six weeks trial. Egg production, egg quality, yolk cholesterol and hormones ($17{\beta}$-estradiol, progesterone) concentrations in plasma and oviduct were analyzed. Egg production of red group was higher (P<0.01) than that of green group. Haugh unit of eggs from red group was higher (P<0.01) than that of blue and green groups. Egg weight of green group was heavier (P<0.05) than that of red group. Shell of blue group was stronger (P<0.05) than that of red and white groups. Shell color of white group was browner (P<0.01) than that of blue and green groups. Yolk cholesterol of red group was higher (P<0.01) than that of others. Plasma $17{\beta}$-estradiol of red group was higher (P<0.05) than that of others at $3^{rd}$ week, but that of white group was highest (P<0.05) at $6^{th}$ week. Oviduct progesterone of green group was higher (P<0.01) than that of others. The result showed that the LED colors affect the reproductive hormone concentrations, egg production, egg weight and egg quality. This study suggested that red LED would be the most appropriate color for floor raising brown laying hens to sustain the egg production when it begins to decline with aging.

• Journal of Dental Rehabilitation and Applied Science
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• v.40 no.2
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• pp.55-63
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• 2024

Purpose: This study aimed to assess the antimicrobial efficacy of an 810-nm infrared diode laser with indocyanine green (ICG) against Staphylococcus aureus on sandblasted, large grit, and acid-etched (SLA) titanium surfaces, comparing its effectiveness with alternative chemical decontamination modalities. Materials and Methods: Biofilms of S. aureus ATCC 25923 were cultured on SLA titanium disks for 48 hours. The biofilms were divided into five treatment groups: control, chlorhexidine gluconate (CHX), tetracycline (TC), ICG, and 810-nm infrared diode laser with ICG (ICG-PDT). After treatment, colony-forming units were quantified to assess surviving bacteria, and viability was confirmed through confocal laser-scanning microscope (CLSM) imaging. Results: All treated groups exhibited a statistically significant reduction in S. aureus (P < 0.05), with notable efficacy in the CHX, TC, and ICG-PDT groups (P < 0.01). While no statistical difference was observed between TC and CHX, the ICG-PDT group demonstrated superior bacterial reduction. CLSM images revealed a higher proportion of dead bacteria stained in red within the ICG-PDT groups. Conclusion: Within the limitations, ICG-PDT effectively reduced S. aureus biofilms on SLA titanium surfaces. Further investigations into alternative decontamination methods and the clinical impact of ICG-PDT on peri-implant diseases are warranted.

• Journal of Korean Society of Forest Science
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• v.103 no.3
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• pp.422-430
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• 2014

This study was conducted to investigate growth changes of DBH, height, crown width, volume, stem biomass, and dead trees after thinning treatments with different thinning intensity for Korean white pine (Pinus koraiensis) plantation. First thinning was applied with 29~69% intensity based on number of trees in 19-yearold plantation, and trees were measured three times: right after thinning (19-year-old), 5 years later (24-yearold), 12 years later (29-year-old). In the case of DBH growth, average DBH growth of heavily thinned plots was 19.6~19.9% higher 5 years later, and 13.3~24.7% higher 12 years later, compared to that of unthinned plots. Initial diameter growth rate was higher than late growth rate. The proportion of large pole candidates ($DBH{\geq}25cm$) was 31% in heavily thinned plot while only 2% was shown in unthinned plot. No difference was shown in height growth depending on plots, and average crown width growth in heavily thinned plots was 30.6~33.3% higher, 5 years later, and 35.0~40.0% higher, 12 years later, compared to that of unthinned plots. Average volume growth of individual trees in heavily thinned plots was 39.8~46.8% higher, 5 years later, and 23.0~52.0% higher, 12 years later, compared to unthinned plots. The maximum volume and biomass per unit area were shown in unthinned plot; the volume and biomass 5 and 12 years later after thinning were $133m^3/ha$ (51 kg/ha) and $344m^3/ha$ (132 kg/ha), respectivily. The significant difference appeared in crown width, volume, and biomass depending on thinning intensity. No dead trees occurred in heavily thinned plots for 12 years after thinning, while mortality rate in unthinned plots was 27.9~37.8%. As a result of analyzing annual increment using cores to determine the timing of second thinning, it suggested that second thinning be suitable around 10 years after first thinning.

• Korean Journal of Poultry Science
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• v.41 no.4
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• pp.241-247
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• 2014

The objective of this experimental was to investigate the effect of dietary Cu-sulfate and Cu-soy proteinate on productive performance and small intestinal microflora. A total 1,000 Hy-Line Brown laying hens (35 weeks old) were randomly allotted to 1 of 5 dietary treatments: Control, Cu-sulfate 50, 100 (50, 100 ppm Cu supplementation as Cu-sulfate) and Cu-SP 50, 100 (50, 100 ppm Cu supplementation as Cu-soy proteinate). Each treatment was replicated 4 times with fifty birds per replication, housed in 2 birds cages. Fifty birds units were arranged according to randomized block design. Feeding trial lasted 5 weeks under 16L : 8D lighting regimen. Hen day egg production was significantly (P<0.05) higher in Cu treated groups than control. Feed intake, broken and shell-less egg production was not significantly influenced by treatment. Eggshell color, eggyolk color, haugh unit, and eggshell thickness were not significantly influenced by treatment. However, eggshell strength was significantly (P<0.05) greater in Cu treated groups than control. Concentration of copper of liver was significantly (P<0.05) greater in Cu treated groups than control. Concentration of zinc and iron of liver were not influenced by treatments. Population of Cl. perfrigens and Lactobacilli in the small intestinal content were significantly (P<0.05) influenced by treatments. Population of Cl. perfrigens decreased and that of Lactobacilli increased in the Cu supplement groups. In conclusion, dietary Cu sulfate and Cu-soy proteinate similarly improves egg production, eggshell strength, and favors intestinal microbial population of laying hens.

• Korean Journal of Poultry Science
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• v.32 no.3
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• pp.211-217
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• 2005

This study was carried out to investigate the effects of Saccharomyces cerevisiae (wild yeast mutant), Saccharomyces cerevisiae hFeHLC (ferritin containgig yeast) and chelated Fe diets on the Productivity and egg qualify of laying hens. A total of 245 'Brown Tetra' layers 35 weeks aged was randomly alloted to seven dietary treatments : 1) control diet no iron added, 2) diet supplemented $0.1\%$ wild yeast mutant (YM03), 3) diet supplemented $1.0\%$ wild yeast mutant (YM03), 4) diet supplemented $0.1\%$ ferritin with yeast (YF04), 5) diet supplemented $1.0\%$ ferritin with yeast (YF04), 6) diet supplemented $0.01\%$ chelated Fe and 7) diet supplemented $0.1\%$ chelated Fe. The egg Production rate was significantly increased in layers 134 Fe supplemented diets (p<0.05). Egg weight was significantly reduced in layers fed $0.1\%$ chelated Fe diet (P<0.05). Fe content of egg yolk was significantly increased in $1.0\%$ YF04 and $0.1\%$ chelated Fe treatments (P<0.05). There were no significant differences in shape index, albumin index and yolk index of eggs of layers fed diets Fe supplementation (P>0.05). The haugh unit of eggs was significantly increased in layers fed YM03, YF04 and chelated Fe supplemented diets (p<0.05). TBA value of egg was significantly increased in different iron Fe treatments except of $0.1\%$ YM03 (P<0.05). The yolk cole. of eggs was significantly increased in $1.0\%$ YF04 diet (P<0.05).

• Pediatric Infection and Vaccine
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• v.3 no.2
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• pp.175-184
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• 1996

Purpose : This study was intended to measure seropositivities and the levels of mumps- and rubella-specific IgG of MMR vaccinees over 17 months of age in Korea. Materials and Methods : From June 1994 to April 1995 we obtained sera from visitors of well baby clinic and patients in Korea University Hospital, who were MMR vaccinees over 17 months of age and had no evidence of immunodeficiency. These 275 study population include 145 males and 130 females. Mumps- and rubella-specific IgG antibody levels were measured by ELISA. Cut-off values for seropositivity were 20 GU(Gamma Unit) in mumps and 0.17 in rubella. Results : 1) As age increased, seropositivities of mumps-specific IgG increased significantly, being 69.0% in 1.5~2 year, 75.0% in 3~4 year, 76.0% in 5~6 year, 90.0% in 7 year, 100% in 8 year, 96.9% in 9 year, 97.4% in 10 year, 97.4% in 11 year, and 96.6% in 12 year of age(p<0.001). 2) As age increased, the levels of mumps-specific IgG antibody(mean${\pm}$standard deviation, GU) increased significantly, being $64.9{\pm}66.5$ in 1.5-2 year, $117.7{\pm}126.4$ in 3~4 year, $152.3{\pm}147.1$ in 5~6 year, $194.3{\pm}168.2$ in 7 year, $258.1{\pm}190.6$ in 8 year, $193.1{\pm}130.1$ in 9 year, $225.7{\pm}119.6$ in 10 year, $220.7{\pm}114.3$ in 11 year, and $222.3{\pm}127.1$ in 12 year of age(p<0.001). There was positive correlation between age and mumps-specific antibody level (r=0.3282, p<0.001). 3) As age increased, seropositivities of rubella-specific IgG decreased significantly, being 72.4% in 1.5~2 year, 75% in 3~4 year, 72% in 5~6 year, 60% in 7 year, 44.4% in 8 year, 40.6% in 9 year, 28.2% in 10 year, 23.1% in 11 year, and 17.2% in 12 year of age(p<0.001). 4) As age increased, rubella-specific IgG decreased significantly, being $0.462{\pm}0.356$ in 1.5~2year, $0.438{\pm}0.306$ in 3~4 year, $0.287{\pm}0.179$ in 5~6 year, $0.204{\pm}0.139$ in 7 year, $0.189{\pm}0.153$ in 8 year, $0.124{\pm}0.121$ in 9 year, $0.093{\pm}0.114$ in 10 year, $0.104{\pm}0.135$ in 11 year, and $0.080{\pm}0.001$ in 12 year of age(p<0.001). There was negative correlation between age and rubella-specific IgG titer (r=-0.551, p<0.001). Conclusions : Eventhough seropositivities and the level of mumps-specific IgG increased as age increased, they are not enough to prevent mumps infection in 1.5 to 6 years of age. Seropositivities and the level of rubella-specific IgG decreased as age increased. Appropriate change in vaccine schedule may be needed to decrease the risks of mumps and rubella infection.