• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.1
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• pp.65-74
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• 2023

This study compared the surface roughness and microbial adhesion characteristics of Omnichroma, a novel composite resin developed using "smart chromatic technology", with those of two other conventional composite resins with different filler compositions. A total of 144 specimens were fabricated using 3 types of composite resins: Omnichroma (nano-spherical), Filtek Z350XT (nanofill), and Tetric N-Ceram (nanohybrid) and, divided into 3 groups of 48. Finishing was performed using tungsten carbide burs. Specimens were then divided into 3 subgroups using different polishing methods: Control, SofLex, and PoGo. Surface roughness was analyzed quantitatively and qualitatively using an atomic force microscope and a scanning electron microscope. Microbial adhesion was assessed by culturing Streptococcus mutans on the specimens for 24 hours and then measuring colony-forming units attached to the upper surface. The surface roughness (Ra) of Omnichroma was 0.123 ㎛ after finishing, and it exhibited a smooth surface compared to the other resins. However, after polishing, there were no significant differences in the surface roughness between the three composite groups, regardless of the polishing methods. The surfaces of the Control subgroups were significantly rougher than those of the SofLex subgroups in all 3 composite groups. However, except for Tetric N-Ceram, there were no significant differences between the Control and PoGo subgroups in the other composite groups. Microbial adhesion assessment showed no significant differences between any of the 3 composite resin subgroups; however, Omnichroma exhibited higher microbial adhesion than the other two composites. No significant correlation was observed between surface roughness and microbial adhesion.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.2
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• pp.168-178
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• 2023

Objectives: This study aimed to compare the physical properties and antibacterial effectiveness of iodoform based root filling pastes, Vitapex^® and Metapex^®, with sodium iodide root filling paste (NaI paste) for primary teeth. Materials and Methods: The physical properties (flowability, film thickness, radiopacity) of the pastes were evaluated according to ISO 6876:2012. The antibacterial activity against Enterococcus faecalis strain (ATCC 6538) was evaluated using a direct contact test. Results: There was no significant statistical difference (p > 0.05) observed in the flow and film thickness of NaI paste when compared to the currently available root canal filling materials. The average flow capacities for Vitapex^®, Metapex^®, and NaI paste were 15.40 mm, 21.25 mm, and 20.01 mm, respectively. The average film thickness for Vitapex^®, Metapex^®, and NaI paste were 33.3 ㎕, 22.6 ㎕, and 25.0 ㎕, respectively. However, NaI paste showed lower radiopacity than the existing materials, and this difference was statistically significant (p < 0.05) NaI paste demonstrated higher antimicrobial activity than the available materials, and this difference was also statistically significant (p < 0.05). Conclusion: Compared to the existing commercialized root canal filling materials, NaI paste exhibited similar performance in terms of flow and film thickness, and superior antimicrobial activity against E. faecalis. Hence, NaI paste could be a promising root filling material for primary teeth and may be a potential alternative to existing materials.

• Journal of Korean Home Economics Education Association
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• v.34 no.4
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• pp.143-161
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• 2022

The aim of this study is to identify the learning performance of online classes using problem-based learning(PBL) for clothing and textiles majors in college with the increased use of online learning tools after the COVID-19 pandemic. In order to achieve this goal, the PBL was developed and applied to the 'Fashion Marketing and Merchandising' class conducted in real-time online at University in North Chungcheong Province, Korea for four weeks. After a four-week PBL class, a survey was conducted on 35 students in the 'Fashion Marketing and Merchandising' class and the 35 completed questionnaires were used for analysis. The measurement tools of this study were self-directed learning, cooperative learning ability, problem-solving ability, and learning achievement regarded as an important learning effect in PBL class. In addition, students' self-reflective essays were also analyzed to examine the educational effect of PBL applying online classes. As a result of this study, bivariate correlations among the four variables, students' self-directed learning, cooperative learning ability, problem-solving ability, and learning achievement were significantly positive. Furthermore, the results of multiple regression analysis showed that the three independent variables had significant effects on students' perceived learning achievement, in the order of cooperative learning ability, self-directed learning, and problem-solving ability. The students' self-reflective essays indicated that problem-based learning worksheet was helpful for identifying problems, and clarifying what they already and what they need to study more. Based on this study, it could be recommended that online class applying PBL could contribute to the improvement of student's learning performance.

• Journal of Mushroom
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• v.21 no.1
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• pp.22-32
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• 2023

To investigate the effect of thinning intensity on environmental factors and ectomycorrhizal mushroom fruiting in forest ecosystems, we studied canopy closure, throughfall, soil temperature, soil moisture, light response of understory vegetation, and ectomycorrhizal mushroom fruiting in a 10-year-old pine forest after 34%, 45%, and 60% thinning. Canopy closure was significantly higher in the 34% treatment and control plots, ranging from 80-85% in April. However, in November, all thinning treatment plots showed a decrease of approximately 5-10% compared with the control plot. The 60% treatment plot had over 200 mm of additional throughfall compared with the control plot, and monthly throughfall was significantly higher by more than 100 mm in October. The soil temperature in each treatment plot increased significantly by up to 1℃ or more compared with the control plot as the thinning rate increased. The soil moisture increased by more than 5% in the thinning treatment plots during rainfall, particularly in the 34% treatment plot, where the rate of moisture decrease was slower. The photosynthetic rate of major tree species (excluding Pinus densiflora)was highest in Quercus mongolica, with a rate of 7 µmolCO₂·m^-2·s^-1. At a lightintensity of 800 μmol·m^-2·s^-1, Q. mongolica showed the highest photosynthetic level of 6 ± 0.3 μmolCO₂·m^-2·s^-1 in the 45% treatment. The photosynthetic rate of Fraxinus sieboldiana and Styrax japonicus increased as the thinning intensity increased. The Shannon-Wiener index of mycorrhizal mushrooms did not significantly differ among treatments, but the fresh weight of mushrooms was approximately 360-840 g higher in the 34% and 45% treatments than in the control. Additionally, the fresh weight of fungi in the 60% treatment was 860 g less than that in the control. There were more individuals of Amanita citrina in the control than in the thinning treatment, while Suillus bovinus numbers increased by more than 10 times in the 34% thinning treatment compared with the control.

• Journal of Korean Port Research
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• v.6 no.2
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• pp.65-92
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• 1992

The Korean central government has not appreciate the full extent of the impact of seaports on the national economy. As a consequence port investment has not been given sufficient priority and capacity has failed to keep pace with demand. The principal reason for this failure is the fact that the linkages (or relationships) of the port transport industry with other sectors have not been quantified and fully appreciated. To overcome this dificiency this paper developed a port input-output model to determine the economic impact of the port industry on the national economy. This impact study was conducted by analysing the impact of the Korean port industry upon the national economy from the macroeconomic viewpoint, and identifying the spreading effects of port investments upon the nation's economy. The analysis of the economic impact of the port industry suggests that its contribution to the Korean economy is substantial. What the model shows is, in quantifiable terms, there are the strong economic linkages between the port industry and the other sectors of the national economy. The contribution of the port industry to the Korean economy was summarised in the Conclusion section.

• Journal of the Korean Orthopaedic Association
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• v.54 no.4
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• pp.336-342
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• 2019

Purpose: To examine the relationship between the progression of a kyphotic deformity and the magnetic resonance imaging (MRI) findings in conservatively treated osteoporotic thoracolumbar compression fracture patients. Materials and Methods: This study categorized the patients who underwent conservative treatment among those patients who underwent treatment under the suspicion of a thoracolumbar compression fracture from January 2007 to March 2016. Among them, this retrospective study included eighty-nine patients with osteoporosis and osteopenia with a bone density of less than -2.0 and single vertebral body fracture. This study examined the MRI of anterior longitudinal ligament or posterior longitudinal ligament injury, superior or inferior endplate disruption, superior of inferior intravertebral disc injury, the presence of low signal intensity on T2-weighted images, and bone edema of intravertebral bodies in fractured intravertebral bodies. Results: In cases where the superior endplate was disrupted or the level of bone edema of the intravertebral bodies was high, the kyphotic angle, wedge angle, and anterior vertebral compression showed remarkably progression. In the case of damage to the anterior longitudinal ligament or the superior disc, only the kyphotic angle was markedly prominent. On the T2-weighted images, low signal intensity lesions showed a high wedge angle and high anterior vertebral compression. On the other hand, there were no significant correlations among the posterior longitudinal ligament injury, inferior endplate disruption, inferior disc injury, and the progression of kyphotic deformity and vertebral compression. The risk factors that increase the kyphotic angle by more than 5° include the presence of injuries to the anterior longitudinal ligament, superior endplate disruption, and superior disc injury, and the risk factors were 21.3, 5.1, and 8.5 times higher than those of the uninjured case, and the risk differed according to the level of bone edema. Conclusion: An osteoporotic thoracolumbar compression fracture in osteoporotic or osteopenic patients, anterior longitudinal ligament injury, superior endplate and intravertebral disc injury, and high level of edema in the MRI were critical factors that increases the risk of kyphotic deformity.

• Laboratory Medicine Online
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• v.2 no.1
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• pp.10-14
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• 2012

Background: Measurement of HbA_1c levels is widely used to diagnose diabetes mellitus and to evaluate and monitor plasma-glucose concentrations over 6-8 weeks. In this study, we evaluated the diagnostic performance of the newly developed latex immunoturbidimetric method by using Autolab HbA_1c. Methods: We analyzed and compared the diagnostic performance of Autolab HbA_1c with that of Toshiba 200FR between April 2009 and July 2009. According to guidelines (EP5-A2, EP6-P, EP9-A2) of the clinical and laboratory standards institute (CLSI), we compared linearity, precision and correlation of Autolab HbA_1c with those of G7 (Tosoh Corp., Kyoto, Japan) by using high-performance liquid chromatography (HPLC) method. Results: Data obtained using Autolab HbA_1c showed good linearity in mixtures of samples with low (3.1%) and high (15.1%) levels of HbA_1c (r²=0.9997). In the analysis of within-run precision of the samples with HbA_1c levels of 5.1% and 12.1%, the SDs were 0.04 and 0.06 and covariances of these samples were 0.8% and 0.5%, respectively. In the Deming regression model, the regression equation was as follows: Autolab HbA_1c=1.0859×Tosoh HPLC-0.6957. Conclusions: In this study, Autolab HbA_1c method showed better performance characteristics than Tosoh G7 did. In reference review, there was no interference of variant hemoglobin. The data acquisition time of Autolab HbA_1c was lower than that of Tosoh G7. The advantages of Autolab HbA_1c are that it can be used as an autoanlyzer in routine chemical analysis, it does not require pre-analytical treatment, and the samples are automatically treated with distilled water for hemolysis.

• Journal of Chest Surgery
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• v.43 no.6
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• pp.588-595
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• 2010

Background: Base on types of tumor, the types of expressed tumor is diverse and the difference in its expression rate is even more various. Due to such reasons an animal model is absolutely needed for a clinical research of lung cancer. The author attempted oncogenesis by cultivating a cell line of non-small cell carcinoma and then injecting it inside thoracic cavities of nude mice. The author conducted quantitative analyses of HER2/neu tumor gene - an epidermal growth factor receptor (EGFR) related to lung cancer, and TGF-${\beta}_1$, which acts as a resistance to cell growth inhibition and malignant degeneration. In order to investigate achievability of the oncogenesis, histological changes and the expression of cancer gene in case of orthotopic lung cancer is necessary. Material and Method: Among 20 immunity-free male BALB/c, five nude mice were selected as the control group and rest as the experimental group. Their weights ranged from 20 to 25 gm (Orient, Japan). After injection of lung cancer line (SW900 G IV) into the pleural cavity of nude mice, They were raised at aseptic room for 8 weeks. HER2/neu was quantitatively analyzed by separating serum from gathered blood via chemiluminiscent immunoassay (CLIA), and immunosandwitch method was applied to quantitatively analyze TGF-${\beta}_1$. SPSS statistical program (SPSS Version 10.0, USA) was implemented for statistical analysis. Student T test was done, and cases in which p-value is less than 0.05 were considered significant. Result: Even after lung cancer was formed in the normal control group or after intentionally injected lung cancer cell line, no amplification of HER2/neu gene showed reaction. However, the exact quantity of TGF-${\beta}_1$ was $28,490{\pm}8,549pg/mL$, and the quantity in the group injected with lung cancer cell was $42,362{\pm}14,449pg/mL$, meaning 1.48 times highly Significant (p<0.483). It proved that HER2/neu gene TGF-${\beta}_1$ had no meaningful interconnection. Conclusion: TGF-${\beta}_1$ gene expressed approximately 1.48 times amplification in comparison to the control group. The amplification of TGF-${\beta}_1$ meant somatic recuperation inhibition mechanism due to carcinogenesis in nude mice was definitely working. It may be implemented as a quantitative analysis that allows early detection of lung cancer in human body.

• Food Engineering Progress
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• v.23 no.1
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• pp.7-15
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• 2019

The impregnation of solid foods into the surrounding hypotonic or hypertonic solution was explored as a method to infuse NaCl in pork loin cube without altering its matrix. Mass transfer kinetics using a diffusive model as the mathematical model for moisture gain/loss and salt gain and the resulting textural properties were studied for the surrounding solutions of NaCl 2.5, 5.0, 10.0 and 15% (w/w). It was possible to access the effects of brine concentration on the direction of the resulting water flow, quantify water and salt transfer, and confirm tenderization effect by salt infusion. For brine concentrations up to 10% it was verified that meat samples gained water, while for processes with 15% concentration, pork loin cubes lost water. The effective diffusion coefficients of salt ranged from 2.43×10^-9 to 3.53×10^-9 m²/s, while for the values of water ranged from 1.22×10^-9 to 1.88×10^-9 m²/s. The diffusive model was able to represent well salt gain rates using a single parameter, i.e. an effective diffusion coefficient of salt through the meat. However, it was not possible to find a characteristic effective diffusion coefficient for water transfer. Within the range of experimental conditions studied, salt-impregnated samples by 5% (w/w) brine were shown with minimum hardness, chewiness and shear force.

• Journal of the Daesoon Academy of Sciences
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• v.21
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• pp.157-195
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• 2013

대순진리회는 '구천응원뇌성보화천존강성상제(이하 '구천상제')'를 주신(主神)으로 신앙하는 종교단체이다. 그렇다면 대순진리회의 '구천상제'와 중국 도교에서 모셔지는 '구천응원뇌성보화천존'(이하 '보화천존')은 어떤 연관성이 있는 것인가? 이런 질문을 토대로 본 글에서는 이 신들의 기원과 칭호, 도세법문(度世法門 : 세상을 제도하고자 펼친 법도) 등의 관점에서 그 차이점과 공통점을 하나씩 비교해 보았다. 먼저 기원이라는 측면에서 '구천상제'와 '보화천존'을 비교해보면, '구천상제'는 천지인 삼계의 최고신으로서 강씨 가문을 선택하여 인간의 육신으로 태어났다. 강씨 성은 상고 신농씨에서 시작되었는데, 고대 문헌에 근거하면 신농씨는 태양신, 남쪽, 불(火) 등으로 상징화된다. 이런 상징들은 '구천상제'가 인간으로 태어날 때 나타난 "하늘이 남북으로 갈라지다", "큰 불덩이가 몸을 덮치다", "천지가 밝아지는도다" 등의 현상들에서 찾아볼 수 있다. 도교의 '보화천존'은 뇌신의 특징을 가지면서 일신(日神), 월신(月神)과 관계를 맺고 있는데, 이런 면들은 신농씨로부터 분석한 '구천상제'의 신적 기원과 일치하고 있다. 또한 도교에서는 신농씨가 다스리던 세상을 중국 상고시대의 가장 이상적인 사회형태로 보고 있는데, 이것을 '구천상제'가 건설하려는 후천선경과 연관 지어 생각해보면 '구천상제'가 신농씨의 후손인 강씨 종가에서 태어난 배경을 이해할 수 있다. 도교의 '보화천존' 역시 중생의 이익을 도모하고, 조화로운 인간세상을 만드는 것을 목표로 삼고 있으며, 이것은 대순진리회 '구천상제'가 행한 대순의 목적과 거의 비슷하다고 볼 수 있다. 다음으로 '구천상제'와 '보화천존'은 칭호에서도 공통점과 차이점을 살펴볼 수 있다. 단적으로 말하자면, '구천상제'에는 '보화천존'에 비해 '강성상제'라는 칭호가 추가되어 있다는 것이다. 또한 도교에서는 '보화천존'을 최고신으로 모시지 않으며, '구천상제' 신앙에서는 '보화천존' 신앙에서와 달리 뇌신과의 관계에 대한 설명을 찾아볼 수 없다. 마지막으로 '구천상제'와 '보화천존'의 도세법문을 비교해보면 첫째, 구천상제는 세상이 혼란, 불공평, 죄악에 빠졌기에 육신으로 인간 세상에 강림한 후 대순진리를 선포하였다. 이와 유사하게 보화천존도 천하와 인간세상을 순시하여 죄악과 겁액을 없앤다는 '순시천하(巡視天下)' 사상이 있다. 물론 여기에는 차이점이 존재하는데, 그 중 하나는 '보화천존'은 순시할 때 인간의 육신으로 화하지 않았다는 점이다. 또 다른 하나는 '보화천존'이 인간 세상에 창교의 방법을 통하여 선경을 건설하고자 하는 목표를 전해주지 않았다는 점이다. '보화천존'은 교리를 가르치거나 신통을 발휘하는 데에만 중점을 두고 있다. 둘째, '구천상제'가 내린 가르침인 해원상생은 후천선경을 건설하기 위한 수단과 과정이다. 도교의 '보화천존'도 인간이 지은 많은 죄악과 겁액은 세상 사람들이 맺은 원한과 관계가 있으므로, 이런 겁액과 죄를 해소하려면 해원부터 해야 한다는 것을 수차례에 걸쳐 언급하고 있다. 도교에서 말하는 '해원'의 구체적인 내용은 주로 인간의 시비, 질병, 겁액에 관한 것이며, 그 해결 방법으로는 주로 마음속으로 『옥추보경』을 읽는 것이다. 이를 '구천상제'의 '해원상생' 가르침과 비교하면 그 사상의 폭이나 깊이, 중요성, 이론적 측면 등에서 비교적 간단한 형태로서 체계적인 면모로까지 나아가지는 못하였다. 셋째, '구천상제' 는 곤경에 처한 사람이 신명의 호칭을 부르면 그에 상응하는 신명이 달려와서 구원해준다는 '소리감응' 방법을 사용하고 있는데, 이 방법은 도교의 '보화천존' 역시 사용하고 있는 것이다. 넷째, '구천상제'는 과오를 범한 사람이 자신의 과오를 뉘우치면, 그 다음에 상제의 용서를 받음으로써 그 원한이 풀리게 된다는 참법(懺法 : 懺悔法)을 세인(世人) 교화에 자주 사용하였다. 물론 이것은 해원상생의 구체적인 적용이라 할 수 있다. 기능면에서 보면 이 방법은 『구천응원뇌성보화천존옥추보참(九天應元雷聲普化天尊玉樞寶懺)』의 참의(懺儀)와 공통되는 점이 있다. 참의는 수도자 스스로 자신의 잘못을 뉘우치고, 수도에 정진하며, 사회의 안정을 도모하고, 포덕에 힘쓰고, 악을 물리치고 선을 널리 펼친다는 것인데, 이런 의미에서 양자는 일치한다고 생각된다. 필자가 생각하건대, 대순진리회의 '구천응원뇌성보화천존강성상제'와 도교의 '구천응원뇌성보화천존' 사이에는 공통점이 아주 많지만 동시에 차이점 또한 적지 않다. 만약 더욱 다양한 자료들을 수집하여 더욱 깊고 광범위한 연구를 진행한다면 한국 대순진리회와 중국 도교, 특히 도교의 뇌법종파(雷法宗派)와의 상관관계를 해석하는 데 큰 도움이 될 것이라 생각한다.