• 한국작물학회지
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• 제63권4호
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• pp.390-398
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• 2018

생식생장기 장기간의 건조와 침수 스트레스 하에서 물억새와 거대1호의 생육 및 양분함량 변화를 비교분석한 결과는 다음과 같다. 1. 건조 처리에 의한 두 억새 종의 형태적 특성 변화는 없었으나, 침수 처리에 의해 거대1호의 초장은 256.6 cm로 증가하였으며 마디수 또한 16.8개로 증가하였다. 2. 물억새의 출수율은 건조 조건에서 18.9%로 감소하였으나 침수 조건에서는 대조구와 통계적 유의성을 보이지 않았다. 거대1호는 대조구와 건조구에서 모두 출수하지 않았으며, 침수처리에 의해 48.6%의 출수율을 보였다. 3. 주요 양분인 유리당, 전질소, 인산, 칼륨, 마그네슘은 두 억새 모두 건조처리구에서 가장 높았으며, 칼슘과 마그네슘의 경우 침수처리구에서 두 억새 모두 3배이상 감소하였다. 4. 이러한 양분 변화는 건조처리에 의해 억새의 노화가 촉진되어 양분 이동이 저해된 결과로 사료되며, 침수 처리는 거대1호의 출수를 촉진한다는 결과를 처음으로 확인하였다.

• Safety and Health at Work
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• 제10권2호
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• pp.229-236
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• 2019

Background: Emerging reports suggest the potential for adverse health effects from exposure to emissions from some additive manufacturing (AM) processes. There is a paucity of real-world data on emissions from AM machines in industrial workplaces and personal exposures among AM operators. Methods: Airborne particle and organic chemical emissions and personal exposures were characterized using real-time and time-integrated sampling techniques in four manufacturing facilities using industrial-scale material extrusion and material jetting AM processes. Results: Using a condensation nuclei counter, number-based particle emission rates (ERs) (number/min) from material extrusion AM machines ranged from $4.1{\times}10^{10}$ (Ultem filament) to $2.2{\times}10^{11}$ [acrylonitrile butadiene styrene and polycarbonate filaments). For these same machines, total volatile organic compound ERs (${\mu}g/min$) ranged from $1.9{\times}10^4$ (acrylonitrile butadiene styrene and polycarbonate) to $9.4{\times}10^4$ (Ultem). For the material jetting machines, the number-based particle ER was higher when the lid was open ($2.3{\times}10^{10}number/min$) than when the lid was closed ($1.5-5.5{\times}10^9number/min$); total volatile organic compound ERs were similar regardless of the lid position. Low levels of acetone, benzene, toluene, and m,p-xylene were common to both AM processes. Carbonyl compounds were detected; however, none were specifically attributed to the AM processes. Personal exposures to metals (aluminum and iron) and eight volatile organic compounds were all below National Institute for Occupational Safety and Health (NIOSH)-recommended exposure levels. Conclusion: Industrial-scale AM machines using thermoplastics and resins released particles and organic vapors into workplace air. More research is needed to understand factors influencing real-world industrial-scale AM process emissions and exposures.

• 마이크로전자및패키징학회지
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• 제25권4호
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• pp.67-74
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• 2018

두께가 $20{\mu}m$이며, 직경이 각기 $100{\mu}m$, $300{\mu}m$, $500{\mu}m$인 p형 $Sb_2Te_3$와 n형 $Bi_2Te_3$ 박막레그들을 전기도금하여 열전박막모듈을 형성한 후, 박막레그의 직경에 따른 출력전압과 출력전력을 비교하였다. $100{\mu}m$ 직경 박막레그들로 구성된 모듈은 ${\Delta}T=36.7K$에서 365 mV, $300{\mu}m$ 직경 박막레그들로 형성한 모듈은 ${\Delta}T=37.5K$에서 142 mV, $500{\mu}m$ 직경 박막레그들로 제작한 모듈은 ${\Delta}T=36.1K$에서 53 mV의 open circuit 전압을 나타내었다. $100{\mu}m$ 직경 박막레그 모듈은 ${\Delta}T=36.7K$에서 $845{\mu}W$, $300{\mu}m$ 직경 박막레그 모듈은 ${\Delta}T=37.5K$에서 $631{\mu}W$, $500{\mu}m$ 직경 박막레그 모듈은 ${\Delta}T=36.1K$에서 $276{\mu}W$의 최대출력전력을 나타내었다.

• 지질공학
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• 제31권3호
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• pp.381-393
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• 2021

농업용 저수지 제체에 대한 그라우팅 주입효과 확인방법을 검증하기 위하여 물리·역학적 방법, 수리학적 방법, 지구물리학적 방법을 적용하여 결과를 분석하였다. 실내시험과 현장시험을 통하여 획득한 데이터들은 그라우팅 주입단계에 따라 ① 그라우팅 이전, ② 그라우팅 중 ③ 그라우팅 직후, ④ 그라우트재재령 28일 이후로 구분하여 획득되었다. 시추과정에서 획득되는 단위중량, 압축강도, 마찰각, 점착력, N값(관입저항치)의 경우 지반 개량을 확인할 수는 있지만, 지반의 불균질성에 기인하는 한계도 나타났다. 현장 투수시험으로 측정된 투수계수는 그라우트재가 고결되기 이전에도 차수성이 확인되어 그라우팅 직후에 저수지 제체의 개량효과를 확인하기에 가장 적합한 것으로 나타났다. 전기비저항탐사는 그라우팅 이전 저수지 제체에 발달하는 포화대와 누수영역 파악 활용에 적합하였다. 표면파탐사(MASW)는 그라우팅 주입 이후에 탄성파속도가 점차적으로 증가하는 경향성이 뚜렷하여 개량효과를 판단하는데 효과적인 것으로 판단되며, 탄성파 속도를 이용하여 동적특성을 산정할 수 있으므로 내진설계의 기초자료로 활용될 수 있을 것으로 기대된다.

• 한국환경보건학회지
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• 제45권5호
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• pp.426-433
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• 2019

Objectives: Zooplankton communities play important roles in aquatic ecosystems as secondary producers that graze on phytoplankton and in turn are preyed upon by planktivorous and juvenile fish. They can shift their distribution, species composition, and abundance in response to environmental changes. Therefore zooplankton communities are important for understanding the energy flow in aquatic ecosystems and can be valuable indicators of environmental conditions. However, zooplankton in streams are still not well-studied, especially in northern Gyeonggi-do Province. This study aims to investigate the zooplankton communities in major streams in northern Gyeonggi-do Province. Methods: Zooplankton is important in the nutrient cycle and energy flow of aquatic ecosystems. Therefore, we surveyed zooplankton and measured temperature, DO, BOD, COD, T-N, T-P, and Chl-a in major streams (Sincheon, Gongneungcheon, Wangsukcheon, and Gapyeongcheon Streams) and stagnant water (Gomoji Reservoir). Results: The water quality in Gapyeongcheon Stream was the highest grade, while that of Gomoji Reservoir was mesoeutrophic and eutrophic during the research period. In the zooplankton community, Nauplius, Rotaria, and Monostyla spp. were dominant in Sincheon, Gongneungcheon, and Wangsukcheon Streams, and the dominance index was also high. In the case of Gapyeongcheon Stream, it was found that water quality and aquatic ecosystem health were good, and the lowest dominance index reflected this. In Gomoji Reservoir, Polyarthra spp., Nauplius, and Bosmina longirostris, which can be easily observed as eutrophication progresses, showed a high dominance rate. Therefore, it is necessary to monitor the progress of eutrophication in further research. Conclusions: We collected data on the zooplankton communities in streams and investigated their characteristics. As a result, specific species were found to be dominant at each survey sites and some of them are known to be observed as eutrophication progresses. Therefore, we should investigate the zooplankton community of streams around us and apply ecological stream management.

• 한방비만학회지
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• 제20권2호
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• pp.69-77
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• 2020

Objectives: In this study, we investigated the antiobesity and antidiabetic effects of polyherbal extract, DM2 consisting of Atractylodis Rhizoma, Anemarrhenae Rhizoma, Cinnamomi Cortex, and Moutan Radicles Cortex in high fat diet-induced obesity mice. Methods: DM2 extract was prepared with a hot water. Six-week-old male C57BL/6N mice were fed a high-fat diet (HFD) for 8 weeks and then administrated with DM2 extract (500 mg/kg, p.o.) for 4 weeks. The changes of physiological markers, body weight (BW), food and water intakes, and the levels of fasting blood glucose (FBG) were measured once a week for 4 weeks in mice. The the serum levels of glucose, insulin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol (T-CHO), triglyceride, and low density lipoprotein cholesterol in sera were measured in mice using autometic chemical analyzer and enzyme linked immunosorbant assay. We also observed the histological changes of liver and pancreatic tissues with Hematoxylin & Eosin staining. Results: In physiological change, the increases of BW, calorie intake, and FBG in HFD-induced obese mice were significantly decreased after administration of DM2 extract for 4 weeks. The decrease of water intake was significantly increased in DM2 extract-administrated mice. In serological change, the administration of DM2 extract in obesity mice was significantly decreased the serum levels of glucose, insulin, T-CHO, AST, and ALT levels. We also found that DM2 extract inhibited the increase of lipid droplets in liver and the structural destruction of pancreatic tissues in obesity mice. Conclusion: Our study demonstrated that DM2 extract has antiobesity antidiabetic effects with body weight loss, decrease of glucose and insulin levels, and lipid accumulation on liver tissue.

• Animal Bioscience
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• 제34권7호
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• pp.1105-1115
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• 2021

Objective: To conserve and utilize the genetic resources of a traditional Chinese indigenous pig breed, Liangshan pig, we assessed the genetic diversity, genetic structure, and genetic distance in this study. Methods: We used 50K single nucleotide polymorphism (SNP) chip for SNP detection of 139 individuals in the Liangshan Pig Conservation Farm. Results: The genetically closed conserved population consisted of five overlapping generations, and the total effective content of the population (Ne) was 15. The whole population was divided into five boar families and one non-boar family. Among them, the effective size of each generation subpopulation continuously decreased. However, the proportion of polymorphic markers (P_N) first decreased and then increased. The average genetic distance of these 139 Liangshan pigs was 0.2823±0.0259, and the average genetic distance of the 14 boars was 0.2723±0.0384. Thus, it can be deduced that the genetic distance changed from generation to generation. In the conserved population, 983 runs of homozygosity (ROH) were detected, and the majority of ROH (80%) were within 100 Mb. The inbreeding coefficient calculated based on ROH showed an average value of 0.026 for the whole population. In addition, the inbreeding coefficient of each generation subpopulation initially increased and then decreased. In the pedigree of the whole conserved population, the error rate of paternal information was more than 11.35% while the maternal information was more than 2.13%. Conclusion: This molecular study of the population genetic structure of Liangshan pig showed loss of genetic diversity during the closed cross-generation reproduction process. It is necessary to improve the mating plan or introduce new outside blood to ensure long-term preservation of Liangshan pig.

• Journal of Animal Science and Technology
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• 제63권2호
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• pp.319-331
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• 2021

Heat stress (HS) causes adverse impacts on pig production and health. A potential biomarker of HS is required to predict its occurrence and thereby better manage pigs under HS. Information about the saliva metabolome in heat-stressed pigs is limited. Therefore, this study was aimed to investigate the effects of acute HS on the saliva metabolome and identify metabolites that could be used as potential biomarkers. Growing pigs (n = 6, 3 boars, and 3 gilts) were raised in a thermal neutral (TN; 25℃) environment for a 5-d adaptation period (CON). After adaptation, the pigs were first exposed to HS (30℃; HS30) and then exposed to higher HS (33℃; HS33) for 24 h. Saliva was collected after adaptation, first HS, and second HS, respectively, for metabolomic analysis using 1H-nuclear magnetic resonance spectroscopy. Four metabolites had significantly variable importance in the projection (VIP > 1; p < 0.05) different levels in TN compared to HS groups from all genders (boars and gilts). However, sex-specific characteristics affected metabolites (glutamate and leucine) by showing the opposite results, indicating that HS was less severe in females than in males. A decrease in creatine levels in males and an increase in creatine phosphate levels in females would have contributed to a protective effect from protein degradation by muscle damage. The results showed that HS led to an alteration in metabolites related to energy and protein. Protection from muscle damage may be attributed to the alteration in protein-related metabolites. However, energy-related metabolites showed opposing results according to sex-specific characteristics, such as sex hormone levels and subcutaneous fat layer. This study had shown that saliva samples could be used as a noninvasive method to evaluate heat-stressed pigs. And the results in this study could be contributed to the development of a diagnostic tool as a noninvasive biomarker for managing heat-stressed pigs.

• 대한지역사회영양학회지
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• 제26권6호
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• pp.495-507
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• 2021

Objectives: This study examined regional differences in the intake of dietary total fat and saturated fatty acid (SFA) and their food sources among Korean adults. We also investigated the associations of SFA intake with metabolic diseases by region. Methods: This study included 13,926 adults (≥ 19y) who participated in the 2016 ~ 2019 Korea National Health and Nutrition Examination Surveys. The regions were divided into urban and rural areas according to the administrative districts where the participants lived. Using dietary data obtained from a 24-h recall, intake of total fat and SFA and their food sources were assessed by region. Metabolic diseases included obesity, abdominal obesity, and elevated total cholesterol and their association with SFA intake by region were examined using multiple logistic regression. Results: Of the participants, 19.6% lived in rural areas. In urban areas, the total fat and SFA intakes were higher than in rural areas: 21.2% of energy (%E) came from total fat and 6.9%E from SFA in urban areas, whereas 18.0%E came from total fat and 5.8%E from SFA in rural areas. The percentage of participants who exceeded the dietary reference intakes for total fat and SFA in urban areas was 16.5% and 41.9%, respectively, but 43.4% of participants in rural areas showed lower intake levels for total fat compared to the reference level. Young adults did not show regional differences in fat intake, and the percentage of subjects who exceeded the reference for SFA was high both in urban (58.5%) and rural (55.7%) areas. Among middle-aged and older adults, intake of fatty acids except for n-3 fatty acid was significantly higher in urban areas than in rural areas. About 69% of older adults in rural areas showed a lower intake of total fat compared to the reference level. The food sources for total fat and SFA were meat, soybean oil, eggs, and milk in both areas. The intake of fat from eggs, milk, mayonnaise, and bread was higher in urban areas, but the intake of fat from white rice and coffee mix was higher in rural areas. The SFA intake was positively associated with elevated serum total cholesterol in urban areas (4th quartile vs. 1st quartile, OR: 1.22, 95% CI: 1.06-1.40, P for trend: 0.043), but not in rural areas. Conclusions: Regional differences in total fat and SFA intakes and their food sources were observed among Korean adults. Our findings may help plan nutritional strategies to ameliorate regional health disparities.

• Journal of Animal Science and Technology
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• 제64권5호
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• pp.937-949
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• 2022

Health concern of dogs is the most important issue for pet owners. People who have companied the dogs long-term provide the utmost cares for their well-being and healthy life. Recently, it was revealed that the population and types of gut microbiota affect the metabolism and immunity of the host. However, there is little information on the gut microbiome of dogs. Hericium erinaceus (H. erinaceus; HE) is one of the well-known medicinal mushrooms and has multiple bioactive components including polyphenol, β-glucan, polysaccharides, ergothioneine, hericerin, erinacines, etc. Here we tested a pet food that contained H. erinaceus for improvement in the gut microbiota environment of aged dogs. A total of 18 dogs, each 11 years old, were utilized. For sixteen weeks, the dogs were fed with 0.4 g of H. erinaceus (HE-L), or 0.8 g (HE-H), or without H. erinaceus (CON) per body weight (kg) with daily diets (n = 6 per group). Taxonomic analysis was performed using metagenomics to investigate the difference in the gut microbiome. Resulting from principal coordinates analysis (PCoA) to confirm the distance difference between the groups, there was a significant difference between HE-H and CON due to weighted Unique fraction metric (Unifrac) distance (p = 0.047), but HE-L did not have a statistical difference compared to that of CON. Additionally, the result of Linear discriminate analysis of effect size (LEfSe) showed that phylum Bacteroidetes in HE-H and its order Bacteroidales increased, compared to that of CON, Additionally, phylum Firmicutes in HE-H, and its genera (Streptococcus, Tyzzerella) were reduced. Furthermore, at the family level, Campylobacteraceae and its genus Campylobacter in HE-H was decreased compared to that of CON. Summarily, our data demonstrated that the intake of H. erinaceus can regulate the gut microbial community in aged dogs, and an adequate supply of HE on pet diets would possibly improve immunity and anti-obesity on gut-microbiota in dogs.