• Journal of Veterinary Science
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• 제19권6호
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• pp.798-807
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• 2018

Several studies have reported the effect of absorption of procyanidins and their contribution to the small intestine. However, differences between dietary interventions of procyanidins and interventions via antibiotic feeding in pigs are rarely reported. Following 16S rRNA gene Illumina MiSeq sequencing, we observed that both procyanidin administration for 2 months (procyanidin-1 group) and continuous antibiotic feeding for 1 month followed by procyanidin for 1 month (procyanidin-2 group) increased the number of operational taxonomic units, as well as the Chao 1 and ACE indices, compared to those in pigs undergoing antibiotic administration for 2 months (antibiotic group). The genera Fibrobacter and Spirochaete were more abundant in the antibiotic group than in the procyanidin-1 and procyanidin-2 groups. Principal component analysis revealed clear separations among the three groups. Additionally, using the online Molecular Ecological Network Analyses pipeline, three co-occurrence networks were constructed; Lactobacillus was in a co-occurrence relationship with Trichococcus and Desulfovibrio and a co-exclusion relationship with Bacillus and Spharerochaeta. Furthermore, metabolic function analysis by phylogenetic investigation of communities by reconstruction of unobserved states demonstrated modulation of pathways involved in the metabolism of carbohydrates, amino acids, energy, and nucleotides. These data suggest that procyanidin influences the gut microbiota and the intestinal metabolic function to produce beneficial effects on metabolic homeostasis.

• 한국미생물·생명공학회지
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• 제51권3호
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• pp.250-256
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• 2023

Cannabis sativa (CS) has been in the spotlight not only for its medical uses but also as a raw material for cosmetics. As fermented cosmetics are known to have various health benefits, they have been extensively researched. Here, we investigated the characteristics of CS stems fermented using various gut microbes. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay and melanin content analysis revealed that melan-a cells containing CS stems fermented with Weissella paramesenteroides (CSWP) showed considerably reduced melanin content. Additionally, CSWP downregulated the expression of several melanogenesis factors, tyrosinase-related protein-1, and tyrosinase-related protein-2. This study suggests that the anti-melanogenic effect of CSWP could provide a new basis for the development of skin-lightening agents.

• 한국구조물진단유지관리공학회 논문집
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• 제17권3호
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• pp.89-96
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• 2013

1990년대 후반부터 사용된 폴리머 콘크리트로 제작된 맨홀은 이 맨홀이 가지고 있는 다양한 장점 때문에 현재까지 널리 이용되고 있다. 그러나, 고유가 시대로 접어들면서 석유화학 재료의 가격인상과 더불어 폴리머 콘크리트의 제조원가가 상승되고 이에 따른 폴리머 콘크리트의 약점이 대두되고 있다. 따라서, 고가의 폴리머 콘크리트로 제작된 맨홀의 뛰어난 휨강도를 대체할 수 있는 경제적인 시멘트 콘크리트 맨홀의 개발이 요구되어 왔다. 본 연구에서는 비정질 칼슘알루미네이트 (Armorphous calcium aluminate, ACA)계의 속경형 시멘트기술을 기반으로 플라이 애쉬와 고로슬래그, 실리카 퓸, 메타카올린 등의 산업부산물을 이용하여 시멘트의 사용량을 최소화시킴으로써 $CO_2$를 저감시킬 수 있는 친환경적인 맨홀용 고인성 콘크리트를 개발하고자 하였다. 연구결과, 경제적이고 친환경적이면서도 요구성능을 만족시키는 시멘트 콘크리트 맨홀을 개발하였다.

• Fisheries and Aquatic Sciences
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• 제17권2호
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• pp.159-165
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• 2014

In this study, Krill Eupausia superba oil was extracted using different solvents and supercritical carbon dioxide (SC-$CO_2$). During SC-$CO_2$ extraction, the pressure was set at 40 MPa and temperatures ranged from $40^{\circ}C$ to $55^{\circ}C$. We examined the differences in volatile compounds and safety profiles among extraction methods. Volatile compounds were determined using the thermal desorption system integrated with gas chromatography-mass spectrometry (GC-MS). Heavy metal content was analyzed by inductively coupled plasma mass spectrometry (ICP-MS). According to our results 10 volatile compounds were identified in krill sample. After SC-$CO_2$ extraction of oil, the concentrations of volatile compounds decreased, but increased after solvent extraction. In krill, heavy metal concentrations remained within the permissible limit. Moreover, Zn and Fe which have health benefits were detected at high concentrations. During a 90 days storage period at different temperatures, microbial activity was found to be lowest in SC-$CO_2$ extracted residues. Thus, the quality of krill oil and the residues obtained using SC-$CO_2$ extraction was higher and the oil was safer than those obtained using conventional solvent extraction. These results can be applied to the food industry to maintain high quality krill products.

• 공학교육연구
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• 제11권2호
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• pp.65-78
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• 2008

오늘날 산학 협력은 기업과 학계 상호간의 발전을 위해 매우 중요한 역할을 담당하고 있다. 기업은 학교 연구 기관의 우수한 자원과 시설을 충분히 이용하여 새로운 제품 개발을 위한 기술을 얻을 수 있는 이점이 있고 학교는 기업 현장의 실제적인 문제에 대한 연구를 시행함으로써 이론적 연구의 실제적 적용이라는 성과를 가질 수가 있다. 그러나 대부분의 산학 협력모델은 주로 대학원 연구 기관과 기업 프로젝터 중심에서 이루어지고 주로 연구 프로젝터의 형태를 띠고 있거나 학생들의 취업을 위한, 현장실습, 기업 현장 인력 보수 교육이 주를 이루고 있다. 하지만 공학 교육의 큰 주체라고 할 수 있는 학부 단위의 교육 과정과는 다소 거리가 있는 것이 현실이며 그러한 학부 단위의 산학 협력 모델은 구축하기에 있어 프로그램의 기획, 재정, 기업의 무관심과 같은 여러 가지 제약이 따르는 것이 현실이다. 이에 본 논문은 기존의 산학 협력 혹은 기업 공모전과는 색다르게 전개 되고 있는 LG 전자 디지털 디스플레이 본부에서 시행 하는 디스플레이 아이디어 공모전을 소개하고 이를 통하여 기업과 학교의 효용성과 국내에서 새로운 산학 협력 모델을 제시 하고자 한다.

• 한국기후변화학회지
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• 제8권4호
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• pp.377-384
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• 2017

Amid growing concerns about energy security, energy prices, economic competitiveness, and climate change, district heating (DH) system has been recognized for its significant benefits and the part it can play in efficiently meeting society's growing energy demands while reducing environmental impacts. Policy makers often need to quantify the fuel and carbon dioxide ($CO_2$) emissions savings of DH system compared to conventional individual heating (IH) system in order to estimate its actual emissions reductions. The objective of this paper is to calculate energy efficiency and $CO_2$ emissions saving, and to propose the future direction for DH system in Korea. DH system achieved total system efficiencies of 67.9% compared to 54.1% for IH system in 2015. DH system reduced $CO_2$ emissions by $381,311ton-CO_2$ (4.1%) compared to IH system. The results suggest that DH system is more preferred than IH system using natural gas. In Korea, the aim is to reduce dependence on fossil fuels and to use energy more efficiently. DH system have significant potential with regard to achieving this aim, because DH system are already integrated with power generation in the electricity since combined heating and power (CHP) are used for heat supply. Although the future conditions for DH may look promising, the current DH system in Korea must be enhanced in order to handle future competition. Thus, the next DH system must be integrated with multiple renewable energy and waste heat energy sources.

• 한국환경보건학회지
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• 제49권6호
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• pp.362-371
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• 2023

Background: PM_2.5 pollution has been a persistent problem in South Korea, with concentrations consistently exceeding World Health Organization (WHO) guidelines. The aging of the population in the country further exacerbates the health impacts of PM_2.5 since older adults are more susceptible to the adverse effects of air pollution. Objectives: This study aims to evaluate how the health impact (premature death) due to long-term exposure to PM_2.5 in South Korea could change in the future according to the trend of change in the country's population structure. Methods: The study employs a relative risk function, which accounts for age-specific relative risks, to assess the changes in premature deaths by age and region at the average annual PM_2.5 concentration for 2022 and at PM_2.5 concentration improvement levels. Premature deaths were estimated using the Global Exposure Mortality Model (GEMM). Results: The findings indicate that the increase in premature deaths resulting from the projected population structure changes up to 2050 would significantly outweigh the health benefits (reduction in premature deaths) compared to 2012. This is primarily attributed to the rising number of premature deaths among the elderly due to population aging. Furthermore, the study suggests that the effectiveness of the current domestic PM_2.5 standard would be halved by 2050 due to the increasing impact of population aging on PM_2.5-related mortality. Conclusions: The study highlights the importance of considering trends in population structure when evaluating the health benefits of air pollution reduction measures. By comparing and evaluating the health benefits in reflection of changes in population structure to the predicted PM_2.5 concentration improvements at the provincial level, a more comprehensive assessment of regional air quality management strategies can be achieved.

• 노동경제논집
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• 제24권1호
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• pp.97-124
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• 2001

자녀양육에 수반되는 시간적 금전적 비용부담이 기혼여성의 노동시장 진입과 경력단절에 가장 큰 영향을 미치는 요인으로 지적한 선행 연구들은 이에 대한 정책적 지원을 강조하였다. 사회복지정책이 발달한 국가에서 세대간 동거(co-residence)는 고령층의 의료 및 부양과 관련된 공적 비용을 사적 비용으로 전환하고, 공식적인 부양을 비공식적인 것으로 대체하는 동시에 기혼여성의 노동공급을 증가시킨다는 관점에서 정책 설정에서 주요한 개선방안으로 인식되고 있다. 본 연구는 "한국노동패널" 2차년도(1999) 자료를 이용하여 부모세대와의 동거상태, 부모 및 기혼여성 본인의 건강상태가 기혼여성의 노동공급에 미치는 영향을 살펴본다. Tobit모형의 추정 결과, 동거 여부, 여성노인과의 동거, 노동시장 근로를 하지 않는 여성노인과의 동거는 동거하는 노인의 건강상태에 관계 없이 기혼여성의 노동공급량에 정(+)의 효과를 미치는 것으로 나타났다. 세대간 동거는 세대간 사적 자원이전 (intergenerational private transfer of resources)을 통하여 기혼여성의 노동공급에 긍정적인 영향올 미치며, 이는 세대간 사적 자원이전이 여성노인을 중심으로 시간자원의 이전이라는 형태를 취하고 있음을 의미한다.

• 한국조경학회지
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• 제31권3호
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• pp.83-90
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• 2003

This study explored effects of urban greenspace on improving atmospheric environment, which is concerned with $CO_2$, SO$_2$ and NO$_2$ uptake, and with reduction of summer air temperatures. The site of this study was focused on Jung-gu in Seoul. Tree density and cover were 1.1 trees/100 $m^2$ and 12.5% respectively for the study area except forest lands. Atmospheric purification by greenspace was associated with changes in tree cover per unit area of each land use type. The mean $CO_2$ storage by woody plants was 19.4t/ha, and annual uptake averaged 2.2t/ha/yr for $CO_2$, 1.9kg/ha/yr for SO$_2$ and 5.0kg/ha/yr for NO$_2$. Entire tree plantings in the study area played a significant role by annually offsetting $CO_2$ emissions of about 1,830t from fossil fuel consumption by 330 persons, SO$_2$ emissions of 1,620kg by 1,080 persons, and NO$_2$ emissions of 4,230kg by 450 persons. The summer air temperature was 3.6$^{\circ}C$ cooler at a location with 54% cover of woody plants and 4.5$^{\circ}C$ cooler at a forest site with 100% cover, compared to a place with no planting. A 10% increase of woody plant cover was estimated to decrease summer air temperature by approximately 0.6$^{\circ}C$ until a certain level of canopy cover. Analyzing data from the Automatic Weather Stations in Seoul revealed that increasing tree cover decreased mean air temperature for the summer season (Jun~Aug) in a nonlinear function. Woody plant cover was the best predictive variable of summer temperature reduction. The results from this study are expected to be useful in emphasizing the environmental benefits and importance of urban greenspace enlargement, and in urging the necessity for planting and management budgets.

• 운동영양학회지
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• 제24권3호
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• pp.13-18
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• 2020

[Purpose] In vivo studies have demonstrated the ergogenic benefits of eleutherococcus senticosus (ES) supplementation. ES has been observed to enhance endurance capacity, improve cardiovascular function, and alter metabolic functions (e.g., increased fat utilization); however, the exact mechanisms involved remain unknown. We aimed to determine whether ES could effectively induce fat loss and improve muscle metabolic profiles through increases in lipolysis- and lipid metabolism-associated protein expression in 3T3-L1 adipocytes and C2C12 skeletal muscle cells, respectively, to uncover the direct effects of ES on adipocytes and skeletal muscle cells. [Methods] Different doses of ES extracts (0.2, 0.5, and 1.0 mg/mL) were added to cells (0.2 ES, 0.5 ES, and 1.0 ES, respectively) for 72 h and compared to the vehicle control (control). [Results] The intracellular triacylglycerol (TG) content significantly decreased (p < 0.05 for 0.2 ES, p < 0.01 for 0.5 ES and 1.0 ES) in 3T3-L1 cells. Adipose triglyceride lipase, which is involved in active lipolysis, was significantly higher in the 1.0 ES group than in the control group (p < 0.01) of 3T3-L1 adipocytes. In C2C12 cells, the mitochondrial protein voltage-dependent anion channel (VDAC) was significantly increased in the 1.0 ES group (p < 0.01). Furthermore, we found that 1.0 ES activated both 5' AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) in skeletal muscle cells (p < 0.01). [Conclusion] These findings suggest that ES extracts decreased TG content, presumably by increasing lipase in adipocytes and metabolism-associated protein expression as well as mitochondrial biogenesis in muscle cells. These effects may corroborate previous in vivo findings regarding the ergogenic effects of ES supplementation.