• Journal of the Korean Chemical Society
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• v.67 no.5
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• pp.339-347
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• 2023

In this study, a nanocomposite of multi-walled carbon nanotubes@poly(p-phenylenediamine)-Prussian blue (MWCNTs@PpPD-PB) was synthesized and employed for the electrochemical detection of hydrogen peroxide (H₂O₂). A straightforward approach was utilized to prepare an electrochemical H₂O₂ sensor using a MWCNTs@PpPD-PB modified glassy carbon electrode, and its electrochemical behavior was investigated through techniques such as electrochemical impedance spectroscopy, cyclic voltammetry, and amperometry. The modified electrode displayed a favorable electrocatalytic response towards the reduction of H₂O₂ in an acidic solution. The developed sensor exhibited linearity in the concentration range of 0.005 mM to 2.225 mM for H₂O₂, with high sensitivity (583.6 ㎂ mM^-1cm^-2) and a low detection limit (0.95 ㎛, S/N = 3) at an applied potential of +0.15 V (vs. Ag/AgCl). Additionally, the sensor demonstrated excellent selectivity, reproducibility, and stability. Moreover, successful detection of H₂O₂ was achieved in real samples.

• Environmental and Resource Economics Review
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• v.31 no.4
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• pp.597-617
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• 2022

In this study, consumption-based greenhouse gas emissions from 1990 to 2021 are calculated by the industry sector, and greenhouse gas emissions transferred due to trade between countries are compared to analyze what implications Korea has. As a result, production-based and consumption-based emissions in the United States, Germany, the EU, and the OECD are gradually decreasing. Production-based emission in Korea is larger than consumption-based emissions because Korean economic structure is import-oriented. However, unlike other developed countries, Korea cannot trade energy by land, so it can be said that it is reasonable to establish a greenhouse gas reduction plan considering Korea's unique characteristics.

• Preventive Nutrition and Food Science
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• v.5 no.2
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• pp.109-113
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• 2000

In this study, a potential mechanism through which the hesperidin might work on the effect was examined in vivo. Male rats were fed a high cholesterol synthetic diet (1%, wt/wt) with hesperidin (0.1%, wt/wt) for 42 days. Activity of hepatic HMG-CoA reductase was significantly lowered by the hesperidin supplement compared to the control. Hesperidin did not significantly alter plasma or hepatic lipids, but tended to lower those lipid levels. Hesperidin also subsequently reduced the fecal neutral sterols compared to the control(253.3mg/d vs.521.9 mg/d). The inhibition of HMG-CoA reductase resulting from the hesperidin supplementation could count for the reduction in fecal neutral sterols that appears to compensate for the decreased cholesterol biosynthesis. The dose of hesperidin in a high choles-terol diet should apparently be more than 0.1% to exhibit the hypocholesterolemic response in these rats. It remains to be determined whether the observed alterations in cholesterol metabolism are specific to the rat or also could be applied to the humans.

• Clinical and Experimental Reproductive Medicine
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• v.30 no.1
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• pp.85-93
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• 2003

Objective : To evaluate the safety and efficacy of selective fetal reduction (SFR) and compare the outcome of twin pregnancy after SFR in multiple pregnancy induced by assisted reproductive technology (ART) with that of natural twin pregnancy. Methods : From September 1995 to March 2002 in Ajou University Hospital, SFR was performed in 79 patients whose gestational sacs were more than 3. Of these 79 patients, 47 patents resulted in twin pregnancy after SFR. SFR was performed using transvaginal intracardiac KCl injection at gestational age of $6{\sim}9$ weeks. Control group was composed of 264 patients with natural twin pregnancy, who delivered after intrauterine pregnancy at 24 weeks, from June 1994 through December 2002. We compared Obstetric and perinatal outcomes between SFR group and natural twin group. Results: Among 47 patients with twin pregnancy after SFR, 2 spontaneous abortion were occurred at intrauterine pregnancy at 8 and 19 weeks. Obstetrical and perinatal outcomes were available in 43 patients. Single intrauterine fetal death was occurred in 1 of 43 (2.3%) patients in SFR group. Incidence of preterm labor, premature rupture of membrane, preeclampsia and placenta previa were similar, but gestational diabetes mellitus (GDM) was occurred more frequently in SFR group (3 (7.0%) vs 4 (1.5%), p=0.02). Mean gestational age, mean birth weight, incidence of discordancy, use of intubation and ventilation, incidence of fetal anomaly, low (<7) Apgar score and intrauterine growth restriction were similar in both groups. Conclusion: Twin pregnancy after SFR has the increased incidence for GDM but other obstetric and perinatal outcome was similar compared with natural twin pregnancy. So SFR is a safe and effective procedure, so we suggest SFR is needed in multifetal pregnancy more than triplet.

• Journal of the Korean Society of Radiology
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• v.83 no.6
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• pp.1286-1297
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• 2022

Purpose To assess the usefulness of various metal artifact reduction (MAR) methods in patients with hip prostheses. Materials and Methods This retrospective study included 47 consecutive patients who underwent hip arthroplasty and dual-energy CT. Conventional polyenergetic image (CI), orthopedic-MAR (OMAR), and virtual monoenergetic image (VMI, 50-200 keV) were tested for MAR. Quantitative analysis was performed in seven regions around the prostheses. Qualitative assessments included evaluation of the degree of artifacts and the presence of secondary artifacts. Results The lowest amount of image noise was observed in the O-MAR, followed by the VMI. O-MAR also showed the lowest artifact index, followed by high-keV VMI in the range of 120-200 keV (soft tissue) or 200 keV (bone). O-MAR had the highest contrast-to-noise ratio (CNR) in regions with severe hypodense artifacts, while VMI had the highest CNR in other regions, including the periprosthetic bone. On assessment of the CI of pelvic soft tissues, VMI showed a higher structural similarity than O-MAR. Upon qualitative analysis, metal artifacts were significantly reduced in O-MAR, followed by that in VMI, while secondary artifacts were the most frequently found in the O-MAR (p < 0.001). Conclusion O-MAR is the best technique for severe MAR, but it can generate secondary artifacts. VMI at high keV can be advantageous for evaluating periprosthetic bone.

• Journal of Chest Surgery
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• v.42 no.3
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• pp.292-298
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• 2009

Background: Surgery for mitral valve disease in children carries both technical and clinical difficulties that are due to both the wide spectrum of morphologic abnormalities and the high incidence of associated cardiac anomalies. The purpose of this study is to assess the outcome of mitral valve surgery for treating congenital mitral regurgitation in children. Material and Method: From 1997 to 2007, 22 children (mean age: 5.4 years) who had congenital mitral regurgitation underwent mitral valve repair. The median age of the patients was 5.4 years old and four patients (18%) were under 12 months of age. 15 patients (68%) had cardiac anomalies. There were 13 cases of ventricular septal defect, 1 case of atrial septal defect and 1 case of supravalvar aortic stenosis. The grade of the preoperative mitral valve regurgitation was II in 4 patients, III in 15 patients and IV in 3. The regurgitation was due to leaflet prolapse in 12 patients, annular dilatation in 4 patients and restrictive leaflet motion in 5 patients. The preoperative MV Z-value and the regurgitation grade were compared with those obtained at follow-up. Result: MV repair was possible in all the patients. 19 patients required reduction annuloplasty and 18 patients required valvuloplasty that included shortening of the chordae, papillary muscle splitting, artificial chordae insertion and cleft closure. There were no early or late deaths. The mitral valve regurgitation after surgery was improved in all patients (absent=10, grade I=5, II=5, III=2). MV repair resulted in reduction of the mitral valve Z-value ($2.2{\pm}2.1$ vs. $0.7{\pm}2.3$, respectively, p<0.01). During the mid-term follow-up period of 3.68 years, reoperation was done in three patients (one with repair and two with replacement) and three patients showed mild progression of their mitral reguration. Conclusion: our experience indicates that mitral valve repair in children with congenital mitral valve regurgitation is an effective and reliable surgical method with a low reoperation rate. A good postoperative outcome can be obtained by preoperatively recognizing the intrinsic mitral valve pathophysiology detected on echocardiography and with the well-designed, aggressive application of the various reconstruction techniques.

• Tuberculosis and Respiratory Diseases
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• v.60 no.4
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• pp.419-425
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• 2006

Background : Severe community-acquired pneumonia (CAP) can develop into respiratory failure that requires mechanical ventilation (MV), which is associated with a higher rate of mortality. It was recently reported that a hydrocortisone infusion in severe CAP patients was associated with a significant reduction in the length of the hospital stay and mortality. This study evaluated efficacy of a hydrocortisone infusion for patients with severe CAP requiring MV. Methods : From February 2005 to July 2005, 13 patients (M : F = 10 : 3, mean age: $68.6{\pm}14.1years$), who were diagnosed with severe CAP and required MV, were enrolled in this study. Hydrocortisone was administered as an intravenous 200mg loading bolus, which was followed by an infusion at a rate of 10mg/hour for 7 days. The control group was comprised of patients with severe CAP requiring MV but in whom corticosteroid was not used before study period. The clinical and physiologic parameters on or by day 8 and the outcome in the hydrocortisone infusion group were compared with those in the control group. Results : 1) There was no significant difference in age, gender ratio, SAPS II, SOFA score, temperature, leukocyte count, PaO2/FiO2 (P/F) ratio, the number of patients with P/F ratio < 200, chest radiograph score, lung injury score and catecholamine-dependent septic shock between the hydrocortisone infusion group and control group at day 1. 2) At day 8, the proportion of patients with an improvement in the P/F ratio ${\geq}100$ and the chest radiograph score was significantly higher in the hydrocortisone infusion group than in the control group (61.5% vs. 15.4%, 76.9% vs. 23.1%, p< 0.05). However, there was no significant difference in the other clinical and physiologic parameters. 3). There was no significant difference in the duration of the MV, ICU stay, hospital stay and 10th and 30th day mortality between the two groups. Conclusion : Hydrocortisone infusion for patients with severe CAP requiring invasive mechanical ventilation may be effective in improving the level of oxygenation and the chest radiograph score.

• Korean Journal of Poultry Science
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• v.44 no.1
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• pp.29-39
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• 2017

This study examined the effects of adding dried blood mixed with Macsumsuk to the feed of broiler chickens. The blood had been dried at $200^{\circ}C$ in an ultra-high-temperature injection system and mixed in a 70:30 proportion of blood meal to Macsumsuk. The experiment consisted of four treatment groups of 150 chickens each. The control group received common broiler feed only, while treatment groups T1, T2, and T3 received feed supplemented with 0.5, 1.0, and 3.0% of the blood meal/Macsumsuk mixture, respectively. The diets were fed for a total of 35 days. Compared with the controls, body weight gain was improved in groups T1 (1,621 g), T2 (1,749 g), and T3 (1,739 g) (1,621-1,749 g vs. 1,448.5 g, respectively) and feed efficiency increased (p<0.01). The carcass rate in group T3 was higher by 83.26% than that in the controls (75.96 %) (p<0.01). The water holding capacity (WHC) increased in groups T1 and T2 (62.27 and 63.80% respectively) compared with controls (p<0.01). The intestine length was longer in groups T1 and T2 (53.98-55.48) than in controls (45.81) (p<0.01). Adding 0.5-1.0% of the dried blood meal Macsumsuk supplement resulted in a significant reduction in the cholesterol content (39.28~47.34 mg/100 g) compared with the controls (50.44 mg/100 g) (p<0.001); furthermore, the proportions of fatty acids including oleic (C18:1n9), ${\gamma}-linoleic$ (C18:3n6), eicosenoic (C20:1n9), and arachidonic (C20:4n6) acids were significantly increased (p<0.01). Compared with controls, the proportion of unsaturated fatty acids (UFA), mono-unsaturated fatty acids (MUFA), and proportion of UFA / SFA in group T1 was (68.66 vs. 69.35%, 51.22 vs 52.00%, and 2.19 vs. 2.26%, respectively) (p<0.05). However, the amino acid content of cystine and methionine of the treatment group (0.43~0.57%) was significantly higher than that of controls (0.38~0.46%) (p<0.05). Overall, supplementing the feed with 0.5-1.0% of the mixture of blood meal Macsumsuk improved productivity by increasing weight gain and feed efficiency, improved meat quality by increasing the water-holding capacity and levels of unsaturated fatty acids, and improved meat color.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1120-1133
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• 2018

The purpose of this study is to validate the failure attribution factors affecting emotional changes after a failed service by local restaurant users, and the relapse effects of the perceived failure of a customer's brand relationship. In this study, the implications of this study can be divided into the null theory and the homogenous theory, in which the study of the relationship between individual belief that influences the null theory and the post-gender emotional response is minimal. The independence of the crash response (angerous VS compassion) has been equally validated as building a belief-gathering-emotion three-step model. First, emotional BRQ (intimate and love) has a reduction effect on controllable geeks, and behavioral BRQ (relative existence) has an extended effect on controllable geeks. From a management perspective, restaurant managers should be less aware of the repeatability of a customer's service failure and call for customer sympathy. Integratedly, restaurant managers must control the customer's perception of service failure and restore the impact of the customer's BRQ on emotional reactions. A variety of service recovery measures should be established and the cerumen should be controlled. In addition, since BRQs have different effects on anger and sympathy (extended VS), different service failure recovery plans should be presented depending on the characteristics of the customer BRQ. For example, measures such as monetary compensation or fair dealing, emotional distribution to close and loving customers, and persuasion of reciprocal benefits to interdependent customers should be developed according to circumstances. This study explored the effectiveness of the geeks after a service failure and has limitations that do not take into account the various regulatory factors in the BRQ-return-Empression process. Thus, in further studies, the effects of adjusting service failure strength should be considered and a more complete model should be built.

• Journal of the Korean Applied Science and Technology
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• v.33 no.2
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• pp.352-360
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• 2016

The purpose of this study was to determine the electrochemical properties develop DSA electrode for sewage sludge solubilization. Using Ir as a main catalyst, the catalyst selected for the sewage sludge solubilization durability and proceeds to functional electrode suitable for sewage sludge electrolysis experiment were obtained the following results. Less mass reduction of the sintering temperature of the main catalyst, Ir coated electrodes, the endothermic reaction zone $300^{\circ}C$ to $500^{\circ}C$, which was selected from a range of experiments. The efficiency of the catalyst results came up to $350^{\circ}C$ best. Each Binder stars (Ta, Sn, W) in this experiment was the biggest catalyst efficiency at $350^{\circ}C$. Used as a binder, $TaCl_5$, $SnCl_4$, $WCl_6$ of the Ta and without affecting the other characteristics of the main catalyst than Sn, W. For the 50% $IrO_2$ electrode is 1.4 V (vs. Ag / AgCl) in a current of about $29mA/cm^2$ was caused to evaluate the effectiveness of the electrode.