• 한국환경과학회지
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• 제28권11호
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• pp.1041-1045
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• 2019

In this study, the KS A ISO Guide 35 was applied to develop analytical standards for heavy metal cadmium using the Korean mussel (Mytilus coruscus) and to evaluate the homogeneity and stability of the sample. Some of the crucial characteristics that reference materials must consist include homogeneity and stability of both intra- and inter-bottles. We tested homogeneity using ANOVA analysis and short-term stability using regression analysis. The variations of cadmium concentrations did not significantly differ between intra- and inter-bottles (F=0.41, p=0.90). For short-term stability verification, cadmium analysis results were not statistically significant as a result of the regression analysis (significance F=0.51, p=0.53). This suggests that we can not dismiss the null hypothesis that there is no significant variation in concentrations of cadmium over time. These results indicated that the cryogenic-milling process has statistically proven the short-term stability for materials from mussels in the chemical analysis of cadmium. Therefore, we propose that the Korean mussel's reference material developed for the proficiency test could be used as a tool to evaluate reliability and consistency in laboratories.

• 한국환경과학회지
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• 제27권12호
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• pp.1271-1277
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• 2018

The National Environmental Specimen Bank (NESB) has been sampling and cryogenically preserving various wildlife specimens to monitor bio-accumulations of chemical pollutants since 2010. Recently, the NESB set up a plan to develop reference materials at their facility to assure the analytical quality of and validate the analytical methods for their monitoring samples. One of the crucial characteristics of reference materials is intra- and inter-bottle homogeneity. In this study, we used ANOVA for total mercury concentrations in some samples to validate their homogeneities after milling and homogenization. We examined the intra- and inter-bottle homogeneities of two cryogenically-milled samples (Korean mussel (Mytilus coruscus) and black-tailed gull's egg (Larus crassirostris). The variations in the total mercury concentrations were not significantly different intra- and inter-bottle (mussel: F=0.74, p=0.67; gull egg: F=1.96, p=0.10). Additionally, the relative standard deviations of the total mercury concentrations showed low values (mussel: 2.02%, gull egg: 1.78%). Therefore, the cryogenic-milling process statistically proves the homogeneity of the materials of mussels and sea gull eggs for chemical analysis for total mercury.

• 산업식품공학
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• 제21권3호
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• pp.233-241
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• 2017

Scaffolds of cell substrates are biophysical platforms for cell attachment, proliferation, and differentiation. They ultimately play a leading-edge role in the regeneration of tissues. Recent studies have shown the potential of bioactive scaffolds (i.e., osteo-inductive) through 3D printing. In this study, rice bran-derived biocomposite was fabricated for fused deposition modeling (FDM)-based 3D printing as a potential bone-graft analogue. Rice bran by-product was blended with poly caprolactone (PCL), a synthetic commercial biodegradable polymer. An extruder with extrusion process molding was adopted to manufacture the newly blended "green material." Processing conditions affected the performance of these blends. Bio-filament composite was characterized using field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDX). Mechanical characterization of bio-filament composite was carried out to determine stress-strain and compressive strength. Biological behaviors of bio-filament composites were also investigated by assessing cell cytotoxicity and water contact angle. EDX results of bio-filament composites indicated the presence of organic compounds. These bio-filament composites were found to have higher tensile strength than conventional PCL filament. They exhibited positive response in cytotoxicity. Biological analysis revealed better compatibility of r-PCL with rice bran. Such rice bran blended bio-filament composite was found to have higher elongation and strength compared to control PCL.

• 한국농공학회논문집
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• 제63권2호
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• pp.19-31
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• 2021

The Ministry of Maritime Affairs and Fisheries has been promoting the 'Fishing Village Specialization Capacity Enhancement Project' to pursue sustainable development of villages such as income generation by using local tangible and intangible resources led by local residents at the village level since 2013. For the fishing village-Specialization capacity enhancement project, six training sessions (mainly in the village unit) are selected by the public offering method, and the project (income generating business, village development project, etc.) is developed for the selected village residents. It has a process of establishing a village project plan (a preliminary plan for village development or a sixth preliminary industrialization plan) based on the training of experts 5 times, practice or excursion 1 time). In this study, four villages in Gangwon-do fishing villages (two coastal villages and two inland water villages) were surveyed on the perception and satisfaction of fishing village development projects before and after training. The survey analysis was conducted by dividing the analysis of resident capacity and satisfaction into personal, interpersonal, and social dimensions. The survey was conducted by distributing a survey before and after training, and a 1:1 survey was conducted according to the residents' cognitive status. Based on the survey, factor analysis, reliability analysis, and analysis using the corresponding sample t-test showed an increase of 0.02 for Yangyang Mulchi fishing village, 0.11 for Samcheok Jangho fishing village, and 0.36 for Hongcheon River fishing industry, but Yanggu Jinmok fishing industry was -0.29, unlike other regions. As a result of this analysis, it has been empirically proven that provision of training projects through resident participation is a very important factor for the success of the fishing village project. Therefore, rather than fostering local leaders, training and community activities to strengthen personal capacities of residents participating in the project, it is necessary to operate the software business with a focus.

• BMB Reports
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• 제55권4호
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• pp.192-197
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• 2022

Cell signals for growth factors depend on the mechanical properties of the extracellular matrix (ECM) surrounding the cells. Microtubule acetylation is involved in the transforming growth factor (TGF)-β-induced myofibroblast differentiation in the soft ECM. However, the mechanism of activation of α-tubulin acetyltransferase 1 (α-TAT1), a major α-tubulin acetyltransferase, in the soft ECM is not well defined. Here, we found that casein kinase 2 (CK2) is required for the TGF-β-induced activation of α-TAT1 that promotes microtubule acetylation in the soft matrix. Genetic mutation and pharmacological inhibition of CK2 catalytic activity specifically reduced microtubule acetylation in the cells cultured on a soft matrix rather than those cultured on a stiff matrix. Immunoprecipitation analysis showed that CK2α, a catalytic subunit of CK2, directly bound to the C-terminal domain of α-TAT1, and this interaction was more prominent in the cells cultured on the soft matrix. Moreover, the substitution of alanine with serine, the 236th amino acid located at the C-terminus, which contains the CK2-binding site of α-TAT1, significantly abrogated the TGF-β-induced microtubule acetylation in the soft matrix, indicating that the successful binding of CK2 and the C-terminus of α-TAT1 led to the phosphorylation of serine at the 236th position of amino acids in α-TAT1 and regulation of its catalytic activity. Taken together, our findings provide novel insights into the molecular mechanisms underlying the TGF-β-induced activation of α-TAT1 in a soft matrix.

• 한국ITS학회 논문지
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• 제21권4호
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• pp.39-49
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• 2022

본 연구에서는 국내 과적차량 단속 대상에서 제외된 소형트럭에 대한 과적 운행 여부를 파악하기 위하여 국도 3개 지점에서 소형트럭의 교통량과 중량 자료를 수집하였다. 그리고 이를 차종별, 요일별, 시간대별로 구분하여 차량 총중량별 과적 분포를 분석하였다. 차종별 분석 결과, 평균적으로 1.5톤 이하 트럭은 6.2%, 2.5톤 이하 트럭은 31.7%, 그리고 3.5톤 이하 트럭은 13.7%의 과적비율로 나타났다. 그리고 동일한 차종에 대하여 수집 지점별로 차이가 나타났고, 소형트럭의 총중량 무게가 적을수록 과적 비율이 높게 나타났다. 요일별 분석 결과, 특정요일에 과적비율이 높게 나타나는 경향은 없었으나 각 지점별로 요일별 예측 가능한 발생 패턴이 있는 것으로 보였다. 그리고 시간대별 분석 결과 모든 지점에서 점심시간 이후 시간(13:00~15:59)대에 과적차량의 비율이 평균적으로 가장 높은 것으로 파악되었다.

• 한국ITS학회 논문지
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• 제21권4호
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• pp.167-189
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• 2022

SAE 기준 자율주행 레벨 2, 3의 경우 완전 자율주행이 불가능하므로 주행에 있어 제어권 전환 과정이 필수적이며, 제어권 전환 소요시간은 자율주행시스템의 안전성을 결정하는 가장 중요한 요소이다. 이에 따라 제어권 전환 소요시간에 대한 연구가 활발히 진행되고 있으나, 각 연구는 독립적으로 시행되어 다양한 연구 결과를 통합한 일반적인 결론 도출이 필요한 실정이다. 따라서, 본 연구는 개별 연구 결과를 통합해서 통합적인 의견을 제시하는 메타분석 기법을 사용하여 제어권 전환 소요시간에 영향을 주는 요인을 분석하였다. 메타분석 결과, 총 10개의 영향요인이 선정되었으며 대부분이 비운전 업무 유형과 관련되어 있었다. 또한, 향후 제어권 전환 및 비운전 업무 연구 수행 방향성 측면에서 시사점을 제시하였다.

• 한국ITS학회 논문지
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• 제22권1호
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• pp.1-15
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• 2023

본 연구에서는 전국 고속도로를 대상으로 화물차 교통사고에 영향을 미치는 주요 요인을 파악하고자 한다. 이를 위해, 고속도로 교통사고 자료들과 포아송 및 음이항 회귀모형을 이용하여 화물차 교통사고 건수 예측모형을 개발하였다. 모형에서 유의한 것으로 확인된 변수는 화물차 연속주행시간지수, 구간연장, 화물차 교통량, 구간내 교량 수, 졸음쉼터 개수이다. 또한, 구축된 예측모형을 이용하여 고속도로 구간별 안전등급(level of service of safety, LOSS)을 도출하였다. 이후 LOSS를 전국 고속도로 네트워크에 표출하여 고속도로 구간별 화물차 교통사고 위험도를 진단하였다. 본 연구에서 개발된 모형과 LOSS는 고속도로에서의 화물차 교통사고 저감을 위한 정책수립의 기초자료로 활용될 것으로 기대된다.

• 대한토목학회논문집
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• 제28권5A호
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• pp.747-756
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• 2008

본 논문에서는 전달길이에 영향을 미치는 인자에 따라 프리텐션 부재가 받는 동적 충격에 의한 영향을 실험적으로 고찰하였다. 이를 위해 긴장재의 직경, 콘크리트의 피복 두께, 구속 철근과 비부착 구간의 유무, 긴장력 도입 방식을 변수로 한 10개의 프리텐션 콘크리트 부재를 제작하고, 긴장재에 부착한 전기 저항식 변형률 게이지를 통하여 부재에 긴장력 도입 시 변형률 변화를 동적으로 측정하였다. 실험 결과, 순간 전달 방식으로 긴장력을 도입할 때 절단단부에서 큰 동적 효과가 발생하는 것을 확인할 수 있었다. 또한, 변형률 변화량으로 각 부재의 긴장력을 비교한 결과, 각 인자에 따라 차이가 존재하는 것을 확인했다. 직경 15.2 mm 강선보다 12.7 mm 강선의 잔류 긴장력 비율이 더 컸으며, 75 mm의 콘크리트 피복 두께만으로도 충분한 구속 효과를 기대할 수 있는 것으로 판단된다. 구속 철근의 영향은 미미했고, 비부착 구간의 영향으로 잔류 긴장력이 향상되었다. 순간 전달 방식보다 지연 전달 방식으로 긴장력을 도입할 때 긴장력 손실이 적은 것으로 확인되었다.

• Biomolecules & Therapeutics
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• 제32권2호
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• pp.214-223
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• 2024

Metabolic abnormalities in the liver are closely associated with diverse metabolic diseases such as non-alcoholic fatty liver disease, type 2 diabetes, and obesity. The aim of this study was to evaluate the ameliorating effect of robinetin (RBN) on the significant pathogenic features of metabolic failure in the liver and to identify the underlying molecular mechanism. RBN significantly decreased triglyceride (TG) accumulation by downregulating lipogenesis-related transcription factors in AML-12 murine hepatocyte cell line. In addition, mice fed with Western diet (WD) containing 0.025% or 0.05% RBN showed reduced liver mass and lipid droplet size, as well as improved plasma insulin levels and homeostatic model assessment of insulin resistance (HOMA-IR) values. CD38 was identified as a target of RBN using the BioAssay database, and its expression was increased in OPA-treated AML-12 cells and liver tissues of WD-fed mice. Furthermore, RBN elicited these effects through its anti-histone acetyltransferase (HAT) activity. Computational simulation revealed that RBN can dock into the HAT domain pocket of p300, a histone acetyltransferase, which leads to the abrogation of its catalytic activity. Additionally, knock-down of p300 using siRNA reduced CD38 expression. The chromatin immunoprecipitation (ChIP) assay showed that p300 occupancy on the promoter region of CD38 was significantly decreased, and H3K9 acetylation levels were diminished in lipid-accumulated AML-12 cells treated with RBN. RBN improves the pathogenic features of metabolic failure by suppressing the p300-CD38 axis through its anti-HAT activity, which suggests that RBN can be used as a new phytoceutical candidate for preventing or improving this condition.