• Journal of the Korean Ceramic Society
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• v.56 no.1
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• pp.71-76
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• 2019

Monochromatic amber phosphor in glasses (PiGs) for automotive LED applications were fabricated with $YAG:Ce^{3+}$, $CaAlSiN_3:Eu^{2+}$ phosphors and Pb-free silicate glass. After synthesis and thickness-thinning process, PiGs were mounted on high-power blue LED to make monochromatic amber LEDs. PiGs were simple mixtures of 566 nm yellow YAG, 615 nm red $CaAlSiN_3:Eu^{2+}$ phosphor and transparent glass frit. The powders were uniaxially pressed and treated again through CIP (cold isostatic pressing) at 200 MPa for 20 min to increase packing density. After conventional thermal treatment at $550^{\circ}C$ for 30 min, PiGs were applied by using GPS (gas pressure sintering) to obtain a fully dense PiG plate. As the phosphor content increased, the density of the sintered body decreased and PiGs containing 30 wt% phosphor had full sintered density. Changes in photoluminescence spectra and color coordination were investigated by varying the ratio of $YAG/CaAlSiN_3$ and the thickness of the plates. Considering the optical spectrum and color coordinates, PiG plates with $240{\mu}m$ thickness showed a color purity of 98% and a wavelength of about 605 nm. Plates exhibit suitable optical characteristics as amber light-converting material for automotive LED applications.

• Journal of Trauma and Injury
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• v.34 no.1
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• pp.39-43
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• 2021

Purpose: Determining appropriate ways to assess health care quality within the National Health Insurance System is of interest to both the Korean government and the medical community. However, in the trauma field, the number of indicators used to evaluate surgical quality is limited. Using data collected over 5 years at Wonju Severance Christian Hospital Trauma Center in Korea, this study aimed to determine whether the unplanned reoperation rate in the field of trauma surgery could be used to assess the quality of an institution's surgical care. Methods: In total, 665 general surgical procedures were performed at the Trauma Center in 453 patients with abdominopelvic injuries from January 2015 to December 2019. Data were collected from the Trauma Center's data registry and medical records, and included information regarding patients' demographic characteristics, the type of index operation, and the reason for unplanned reoperations. Results: A total of 453 index operations were evaluated. The proportion of patients with an Injury Severity Score (ISS) >15 was 48-70% over the 5-year period, with an unplanned reoperation rate of 2.1-9.3%. Patients had an average ISS score of 17.5, while the average Abbreviated Injury Scale Score was 2.87. Unplanned reoperations were required in about 7% of patients. The most common complications requiring reoperation were recurrent bleeding (26.9%), wound problems (26.9%), intestinal infarction (15.4%), and anastomosis site leakage (7.7%). The procedures most frequently requiring unplanned reoperations were bowel surgery (segmental resection, primary repair, enterostomy, etc.) (24.5%) and preperitoneal pelvic packing (10.6%). Conclusions: The proportion of reoperations was confirmed to be affected by injury severity.

• Development and Reproduction
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• v.24 no.4
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• pp.249-261
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• 2020

Spermatogonial stem cells (SSCs) have stemness characteristics, including germ cell-specific imprints that allow them to form gametes. Spermatogenesis involves changes in gene expression such as a transition from expression of somatic to germ cell-specific genes, global repression of gene expression, meiotic sex chromosome inactivation, highly condensed packing of the nucleus with protamines, and morphogenesis. These step-by-step processes finally generate spermatozoa that are fertilization competent. Dynamic epigenetic modifications also confer totipotency to germ cells after fertilization. Primordial germ cells (PGCs) in embryos do not enter meiosis, remain in the proliferative stage, and are referred to as gonocytes, before entering quiescence. Gonocytes develop into SSCs at about 6 days after birth in rodents. Although chromatin structural modification by Polycomb is essential for gene silencing in mammals, and epigenetic changes are critical in spermatogenesis, a comprehensive understanding of transcriptional regulation is lacking. Recently, we evaluated the expression profiles of Yin Yang 1 (YY1) and CP2c in the gonads of E14.5 and 12-week-old mice. YY1 localizes at the nucleus and/or cytoplasm at specific stages of spermatogenesis, possibly by interaction with CP2c and YY1-interacting transcription factor. In the present article, we discuss the possible roles of YY1 and CP2c in spermatogenesis and stemness based on our results and a review of the relevant literature.

• Journal of the Korean Society for Heat Treatment
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• v.35 no.3
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• pp.121-129
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• 2022

Recently the growth of the renewable energy production has caused the flexible operation in LNG combined cycle power plant. Due to the rapid start and stop operations, large CrMoV castings used for turbine casings and valve bodies could be distorted and lead to replacement or welding repair. This study was performed to find out the characteristics of the repair welding for a damaged CrMoV casting steel. A typical field repair method (arc & TIG welding) was applied to making specimens. The degraded N2 packing head sample from the steam turbine was used. The evaluations of weldments were carried out in terms of microstructural characterization, microhardness measurements, tensile, creep-rupture and fatigue tests. Color etching was also applied for better understanding of welding microstructures. As the boundary between HAZ and base material was deteriorated by welding, it caused microstructural changes formed during PWHT and the shortening of the remaining residual life. By comparing the properties according to repair welding method, it was possible to derive what important welding factors were. As a result, arc welding method is more suitable for repair welding on CrMoV castings.

• Journal of Chest Surgery
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• v.56 no.2
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• pp.128-135
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• 2023

Background: Pneumonia caused by severe acute respiratory syndrome coronavirus 2 can cause acute respiratory distress syndrome, often requiring prolonged mechanical ventilation and eventually tracheostomy. Both procedures occur in isolation units where personal protective equipment is needed. Additionally, the high bleeding risk in patients with extracorporeal membrane oxygenation (ECMO) places a great strain on surgeons. We investigated the clinical characteristics and outcomes of percutaneous dilatational tracheostomy (PDT) in patients with coronavirus disease 2019 (COVID-19) supported by ECMO, and compared the outcomes of patients with and without ECMO. Methods: This retrospective, single-center, observational study included patients with severe COVID-19 who underwent elective PDT (n=29) from April 1, 2020, to October 31, 2021. The patients were divided into ECMO and non-ECMO groups. Data were collected from electronic medical records at Ajou University Hospital in Suwon, Korea. Results: Twenty-nine COVID-19 patients underwent PDT (24 men [82.8%] and 5 women [17.2%]; median age, 61 years; range, 26-87 years; interquartile range, 54-71 years). The mean procedure time was 17±10.07 minutes. No clinically or statistically significant difference in procedure time was noted between the ECMO and non-ECMO groups (16.35±7.34 vs. 18.25±13.32, p=0.661). Overall, 12 patients (41.4%) had minor complications; 10 had mild subdermal bleeding from the skin incision, which was resolved with local gauze packing, and 2 (6.9%) had dislodgement. No healthcare provider infection was reported. Conclusion: Our PDT approach is safe for patients and healthcare providers. With bronchoscopy assistance, PDT can be performed quickly and easily even in isolation units and with acceptable risk, regardless of the hypo-coagulable condition of patients on ECMO.

• Journal of Applied Biological Chemistry
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• v.55 no.4
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• pp.267-272
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• 2012

We investigated that electron beam irradiation is the effective method to control the sprouting of sweetpotato roots without changing of food quality characteristics. In 12 and $25^{\circ}C$ storage after electron beam irradiation, all control samples were sprouted from 6 and 4 weeks after storage, respectively. The sprouting rate of control increased with time and the rate reached to 11.2-12.4 and 70.5-74.2% at 8 weeks after 12 and $25^{\circ}C$ storage. Also, the sprouting of middle and below positioning sweetpotato roots at 12 and $25^{\circ}C$ storage after irradiation reached to 8.6-11.3 and 42.7-48.7% after a storage period of 8 weeks, respectively. However, the sprouting of all sweetpotato roots stored at $4^{\circ}C$ and upper (0-7 cm) positioning samples of box stored at 12 and $25^{\circ}C$ with electron beam was completely inhibited due to increase peroxidase and indole acetic acid (IAA) oxidase activity. Also, all samples with electron beam such as hardness, pH, sugar content, weight loss, and vitamin C and dacarotene content did not differ from that of the control. Therefore, if electron beam will be irradiated to sweetpotato roots above 0.1 kGy before packing, it will effectively inhibit their sprouting stored at $25^{\circ}C$ without the change of food quality characteristics.

• Design & Manufacturing
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• v.13 no.2
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• pp.30-36
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• 2019

Traditional cell culture(2-dimensional) is the method that provide a nutrient and environment on a flat surface to cultivate cells into a single layer. Since the cell characteristics of 2D culture method is different from the characteristics of the cells cultured in the body, attempts to cultivate the cells in an environment similar to the body environment are actively proceeding in the industry, academy, and research institutes. In this study, we will develop a technology to fabricate micro-structures capable of culturing cells on surfaces with various curvatures, surface shapes, and characteristics. In order to fabricate the hemispheric plastic structure(thickness $50{\mu}m$), plastic preform mold (hereinafter as "preform mold") corresponding to the hemisphere was first prepared by injection molding in order to fabricate a two - layer structure to be combined with a flat plastic film. Then, thermoplastic polymer dissolved in an organic solvent was solidified on a preform mold. As a preliminary study, we proposed injection molding conditions that can minimize X/Y/Z axis deflection value. The effects of the following conditions on the preform mold were analyzed through injection molding CAE, [(1) coolant inlet temperature, (2) injection time, (3) packing pressure, (4) volume-pressure (V/P). As a result, the injection molding process conditions (cooling water inlet temperature, injection time, holding pressure condition (V / P conversion point and holding pressure size)) which can minimize the deformation amount of the preform mold were derived through CAE without applying the experimental design method. Also, the derived injection molding process conditions were applied during actual injection molding and the degree of deformation of the formed preform mold was compared with the analysis results. It is expected that plastic film having various shapes in addition to hemispherical shape using the preform mold produced through this study will be useful for the molding preform molding technology and cast molding technology.

• Food Science of Animal Resources
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• v.27 no.1
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• pp.80-86
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• 2007

This experiment was conducted to investigate the changes of pork meat quality characteristics exposed to ozone gas for 5, 10, and 15 min and then vacuum packaged during storage for 0, 5, 10, 15, and 20 day at $4^{\circ}C$. The ozone gas exposed groups of pork loin cuts (OZM) had slightly higher pH value compared to the control at day 0 and 5 (p<0.01). The 15 min exposure of ozone gas groups showed significantly (p<0.01) higher TBARS value than that of control at the day 15 and 20. However, there was no significant difference in all groups at day 0,5, and 10. The CIE $L^*$ and $b^*$ values of OZM showed no significant difference between control and ozone gas treated groups during storage. The loin cut color of ozone gas exposure for 15 min had significantly lower CIE $a^*$ values than the other groups at day 0,5, and 15 (p<0.01). The aerobic plate count and coliform bacteria count of pork loin cuts exposed ozone gas significantly (p<0.01) was reduced at day 0 by about $0.45-1.04\;log_{10}CFU/g$ and $0.26-0.30\;log_{10}CFU/g$, respectively. As ozone gas exposure time extended, the aerobic plate count and coliform bacteria count of OZM were increased at day 0, 5, and 10 (p<0.01). However, there were no significant differences observed among groups at day 20 in the counts of aerobic and coliform bacteria. In conclusion, the meat cuts exposed to ozone gas for 5 and 10 min before packing may be a reasonable packing method regarding the effects of ozone level on meat oxidation, color change and microbial reduction.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.282-282
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• 2017

The many factors such as sugar content, moisture, type of bacteria which predominate, buffering capacity, packing and sealing are known to be associated with silage fermentation quality. Among the sugar content are particularly important, because effective silage ensiling relies on the fermentation of sugar content to lactic acid by lactic acid bacteria. Sugar content is also known to affect the protein utilization of rumen. This study was conducted to observe the effect of water soluble carbohydrates on fermentation characteristics and in vitro digestibility of whole crop wheat silage. This experiment was used standard cultivars (Cheongwoo, Hordeum balgare L) and solid breeding line of whole crop wheat. The materials harvested at the 30 after heading day and chopped for making silage, and using this silage carried out in vitro digestibility for 6, 12, 24 and 48 hours. For the feed value, crude protein, NDF, ADF contents showed slightly higher than the before ensiling and TDN contents were slightly lower compared to the before ensiling, but did not show the significantly different. For the sugar contents, fructose and glucose contents were decreased in the after ensiling compared to the before ensiling, there were more reduced at the containing high sugar content wheat. The pH value was lower at containing high sugar content wheat. lactic acid content was significantly higher at the containing high sugar content wheat. Therefore, there was profitable to the production of high quality wheat silage at the higher the sugar content. In in vitro digestibility test, containing high sugar content HW34line showed significantly higher dry matter digestibility at 6 and 12 hours of incubation and amount of NH3-N lower other line in all incubation time. Therefore, there was profitable to the production of high quality wheat silage at the higher the sugar content.

• Korean Journal of Health Education and Promotion
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• v.16 no.2
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• pp.19-40
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• 1999

In order to ascertain the attitudes of residents to their health and the National Health Promotion Law, surveyors interviewed 1,220 subjects, 1% of men and women in Kyungsan city, who were twenty-year-old or more. The major findings are as follows: Men and women were 48.2% and 51.8%, respectively. The recognition rate of enacting and enforcing this law is 59.2% of men and 51.3% of women. With regard to the behavioral attitude to the health in the distinction of sex and age, current smokers are 31.2% of the interviewees, 61.6% of the men and 3.3% of the women. Current drinkers are 35.1%, 59.5% of the men and 12.3% of the women, but on the other hand there is little significance in the distinction of age. The acknowledgement proportion of enacting and enforcing this law is 59.2% of male and 51.3% of female. In terms of the recognition rate of the contents according to the general characteristics of interviewees, it appears that the indication of a warning expression on a packing paper of cigarette case and a liquor bottle is 92.4% and also the designation of a smoking free area in public facilities is 94.8%. Prohibition of cigarette-sale to the teenagers who are under 19, is 96.0%. Considering these facts, the recognition rate is high. On the contrary, 48.8% is accounted for encouraging a medical check-up before marriage which is in a low position. As a result of multiple behavior as a independent educational level, marital significant variables. In case of having undergone a periodic medical examination the recognition rate was high whereas frequent exercise led to the low recognition rate. Concerning the details of the undertaking in accordance with each factor of general characteristics, the greater part of them have been appraised successfully whether it is recognized or not. On the other side, no effect got answered about the result of the undertaking subjects to general and peculiar behavior attitude towards health was in effect or not. A great majority approved of more reinforcement of legal regulation about smoking and drinking regardless of whether they perceived the details of the law of promotion of National Health Promotion Law or not. Additionally there was significant difference in reinforcing legal regulation of smoking and drinking in compliance with the attitude of the substance of this law. With regard to education, public relations and evaluation about national health through public health centers by our government, the younger and the higher in education they are, the more deficient they feel. First of all, those who were aware of the enforcement of this law as well as plenty of scarcity answered that better service of disease prevention had to be expanded than ever. In consideration of the above-stated results, the education to public health and the business of public relations should be reinforced and a practical campaign for health life should also spread out for the purpose of encouraging to practise healthy life-style.