• Asian Pacific Journal of Cancer Prevention
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• v.16 no.12
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• pp.5089-5094
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• 2015

FADS1 (fatty acid desaturase 1) plays a crucial role in fatty acid metabolism, and it was recently reported to be involved in tumorigenesis. However, the role of FADS1 expression in esophageal squamous cell carcinoma (ESCC) remains unknown. In the current study, we investigated the expression and clinical pathologic and prognostic significance of FADS1 in ESCC. Immunohistochemical analyses revealed that 58.2% (146/251) of the ESCC tissues had low levels of FADS1 expression, whereas 41.8% (105/251) exhibited high levels of FADS1 expression. In positive cases, FADS1 expression was detected in the cytoplasm of cells. Correlation analyses demonstrated that FADS1 expression was significantly correlated with tumor location (p=0.025) but not with age, gender, histological grade, tumor status, nodal status or TNM staging. Furthermore, patients with tumors expressing high levels of FADS1had a longer disease-free survival time (p<0.001) and overall survival time (p <0.001). Univariate and multivariate analyses revealed that, along with nodal status, FADS1 expression was an independent and significant predictive factor (p<0.001). In conclusion, our study suggested that FADS1 might be a valuable biomarker and potential therapeutic target for ESCC.

• Journal of Animal Science and Technology
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• v.55 no.2
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• pp.147-153
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• 2013

Lipid metabolism in mature male mice may be different from immature male mice, but the relationship of lipid metabolism, especially n-6 fatty acid metabolism, and sexual maturation is not clearly established. This study was carried out to elucidate whether sexual maturation may affect the metabolism of functional n-6 fatty acids of lipid components by investigating the composition of fatty acids in the longissimus muscle tissues of mature and immature male mice with GC and analyzing the expression of genes and proteins for synthesis of n-6 fatty acids with real-time PCR and western blotting, respectively. Mature male mice showed significantly higher testosterone level in the sera. Similarly, n-6 fatty acids, levels of linoleic acid (LA 18:2n-6) and total n-6 PUFA (Polyunsaturated fatty acids) were increased, but the levels of ${\gamma}$-linolenic acid (GLA; 18:3n-6), dihomo-${\gamma}$-linolenic acid (DGLA; 20:3n-6) and arachidonic acid (AA; 20:4 n-6) were decreased in the mature male mice. mRNA levels of ${\Delta}5$-desaturase (FASD1) and elongase (ELOVL5) genes related to n-6 fatty acid metabolism increased. However, the level of FADS1 protein only increased in mature male mice. In conclusion, this study suggested that sexual maturation of male mice affected n-6 fatty acid metabolism by stimulating the expression of enzyme FADS1 of n-6 PUFA metabolism.

• Animal Bioscience
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• v.34 no.4
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• pp.662-669
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• 2021

Objective: Effects of linseed oil (LO) supplementation on the fat content and fatty acid profile of breast meat, and the expression of three genes in the liver, breast muscle and fat tissues of commercial 154-day-old hybrid male turkeys were investigated. Methods: The animals in the control group were fed a commercially available feed and received no LO supplementation (n = 70), whereas animals in the LO group (n = 70) were fed the same basic diet supplemented with LO (day 15 to 21, 0.5%; day 22 to 112, 1%). The effect of dietary LO supplementation on fatty acid composition of breast muscle was examined by gas chromatography, and the expression of fatty acid desaturase 2 (FADS2), peroxisome proliferator activated receptor gamma (PPARγ), and insulin-like growth factor 1 (IGF1) genes was analysed by means of quantitative reverse transcription polymerase chain reaction. Results: The LO supplementation affected the fatty acid composition of breast muscle. Hepatic FADS2 levels were considerably lower (p<0.001), while adipose tissue expression was higher (p<0.05) in the control compared to the LO group. The PPARγ expression was lower (p<0.05), whereas IGF1 was higher (p<0.05) in the fat of control animals. There were no significant (p>0.05) differences in FADS2, PPARγ, and IGF1 gene expressions of breast muscle; however, omega-6/omega-3 ratio of breast muscle substantially decreased (p<0.001) in the LO group compared to control. Conclusion: Fatty acid composition of breast meat was positively influenced by LO supplementation without deterioration of fattening parameters. Remarkably, increased FADS2 expression in the liver of LO supplemented animals was associated with a significantly decreased omega-6/omega-3 ratio, providing a potentially healthier meat product for human consumption. Increased PPARγ expression in fat tissue of the LO group was not associated with fat content of muscle, whereas a decreased IGF1 expression in fat tissue was associated with a trend of decreasing fat content in muscle of the experimental LO group.

• Nutrition Research and Practice
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• v.13 no.4
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• pp.286-294
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• 2019

BACKGROUND/OBJECTIVES: Docosahexaenoic acid (DHA), an n-3 long chain polyunsaturated fatty acid (LCPUFA), is acquired by dietary intake or the in vivo conversion of ${\alpha}$-linolenic acid. Many enzymes participating in LCPUFA synthesis are regulated by peroxisome proliferator-activated receptor alpha ($PPAR{\alpha}$). Therefore, it was hypothesized that the tissue accretion of endogenously synthesized DHA could be modified by $PPAR{\alpha}$. MATERIALS/METHODS: The tissue DHA concentrations and mRNA levels of genes participating in DHA biosynthesis were compared among $PPAR{\alpha}$ homozygous (KO), heterozygous (HZ), and wild type (WT) mice (Exp I), and between WT mice treated with clofibrate ($PPAR{\alpha}$ agonist) or those not treated (Exp II). In ExpII, the expression levels of the proteins associated with DHA function in the brain cortex and retina were also measured. An n3-PUFA depleted/replenished regimen was applied to mitigate the confounding effects of maternal DHA. RESULTS: $PPAR{\alpha}$ ablation reduced the hepatic Acox, Fads1, and Fads2 mRNA levels, as well as the DHA concentration in the liver, but not in the brain cortex. In contrast, $PPAR{\alpha}$ activation increased hepatic Acox, Fads1, Fads2, and Elovl5 mRNA levels, but reduced the DHA concentrations in the liver, retina, and phospholipid of brain cortex, and decreased mRNA and protein levels of the brain-derived neurotrophic factor in brain cortex. CONCLUSIONS: LCPUFA enzyme expression was altered by $PPAR{\alpha}$. Either $PPAR{\alpha}$ deficiency or activation-decreased tissue DHA concentration is a stimulus for further studies to determine the functional significance.

• Structural Engineering and Mechanics
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• v.47 no.1
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• pp.131-147
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• 2013

In this paper, constraint-based fracture mechanics analyses of hollow cylinders with internal circumferential crack under tensile loading are conducted. Finite element analyses of the cracked cylinders are carried out to determine the fracture parameters including elastic T-stresses, and fully-plastic J-integrals. Linear elastic finite element analysis is conducted to obtain the T-stresses, and elastic-plastic analysis is conducted to obtain the fully plastic J-integrals. A wide range of cylinder geometries are studied, with cylinder radius ratios of $r_i/r_o$ = 0.2 to 0.8 and crack depth ratio a/t = 0.2 to 0.8. Fully plastic J-integrals are obtained for Ramberg-Osgood power law hardening material of n = 3, 5 and 10. These fracture parameters are then used to construct conventional and constraint-based failure assessment diagrams (FADs) to determine the maximum load carrying capacity of cracked cylinders. It is demonstrated that these tensile loaded cylinders with circumferential cracks are under low constraint conditions, and the load carrying capacity are higher when the low constraint effects are properly accounted for, using constraint-based FADs, comparing to the predictions from the conventional FADs.

• The Korean Journal of Financial Management
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• v.9 no.1
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• pp.135-175
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• 1992

본 논문은 주가(株價)의 변동성검증모형(變動性檢證模型)을 한국주식시장(韓國株式市場)에 적용하여 시장의 효율성을(效率性) 검증하였다. 1975년부터 1990년까지 의 17년 기간중 Shiller[81a], Mankiw-Romer-Shapiro[85], West[88b]의 모형을 이용하여 검증한 결과, 높은 수준의 과잉변동성(過剩變動性)이 발견되었다. 그러나 이러한 주가의 과잉 변동성을 시장이 비효율적이라는 증거로 간주하기는 어렵다. 왜냐하면 이들 모형의 가정 중의 하나인 할인율이 일정하다는 가정을 완화시켜 다시 검증한 결과는 오히려 과잉변동성 중에서 많은 부분이 감소하는 것으로 나타났기 때문이다. 다시말해서 주가에 과잉변동성이 존재하는 것은 시장이 비효율적이라기 보다는 기간에 따른 할인율의 변동폭이 큰 데에 원인이 있는 것으로 해석된다. 따라서 할인율(割引率)의 변동원인(變動原因)을 조사하여 주식시장의 효율성을 분석하였다. 주가의 일부는 랜덤웍의 요소에 의해 결정되고, 나머지 일부는 평균회귀(平均回歸) fads(mean reverting fads)에 의해 결정된다고 가정하여 검증한 결과, 후자에 의해 설명된 비율이 매우 높게 나타났다. 즉 한국주식시장에서의 투자자는 교란거래(攪亂去來)(noise trading)나 피드백거래(去來)(feedback trading) 등의 비합리적인 투자행동을 취하고 있으며, 이러한 비합리적인 행동에 의해 주가변동의 $60{\sim}80%$가 설명되는 것으로 보인다.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.2
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• pp.86-92
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• 2019

The aim of this study was to investigate effects of hyaluronidase during IVM on oocyte maturation, oxidative stress status, expression of cumulus expansion-related (PTX, pentraxin; GJA1, gap junction protein alpha 1; PTGS2, prostaglandin-endoperoxide synthase 2) and fatty acid metabolism-related (FADS1, delta-6 desaturase; FADS2, delta-5 desaturase; PPARα, peroxisome proliferator-activated receptor-alpha) mRNA, and embryonic development of porcine oocytes. The cumulus-oocyte complexes (COCs) were incubated with 0.1 mg/mL hyaluronidase for 44 h. Cumulus expansion was measured at 22 h after maturation. At 44 h after maturation, nuclear maturation, intracellular glutathione (GSH) and reactive oxygen species (ROS) levels were measured. Gene expression in cumulus cells was analyzed using real time PCR. The cleavage rate and blastocyst formation were evaluated at Day 2 and 7 after insemination. In results, expansion of cumulus cells was suppressed by treatment of hyaluronidase at 22 h after maturation. Intracellular GSH level was reduced by hyaluronidase treatment (p < 0.05). On the other hand, hyaluronidase increased ROS levels in oocytes (p < 0.05). Only PTGS2 mRNA was enhanced in COCs by hyaluronidase (p < 0.05). Population of oocytes reached at metaphase II stage was higher in control group than hyaluronidase treated group (p < 0.05). Both of cleavage rate and blastocyst formation were higher in control group than hyaluronidase group (p < 0.05). Our present results showed that developmental competence of porcine oocytes could be reduce by hyaluronidase via inducing oxidative stress during maturation process and it might be associated with prostaglandin synthesis. Therefore, we suggest that suppression of cumulus expansion of COCs could induce oxidative stress and decrease nuclear maturation via reduction of GSH synthesis and it caused to decrease developmental competence of mammalian oocytes.

• Development and Reproduction
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• v.22 no.4
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• pp.297-307
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• 2018

The objective of this study was to evaluate the effects of alpha-linolenic acid (ALA) during in vitro maturation (IVM) on cumulus expansion, nuclear maturation, fertilization capacity and subsequent development in porcine oocytes. The oocytes were incubated with 0, 25, 50, and $100{\mu}M$ ALA. Cumulus expansion was measured at 22 h, and gene expresison and nuclear maturation were analyzed at 44 h after maturation. Then, mature oocytes with ALA were inseminated, and fertilization parameters and embryo development were evaluated. In results, both of cumulus expansion and nuclear maturation were increased in $50{\mu}M$ ALA groups compared to control groups (p<0.05). However, expression of gap junction protein alpha 1 (GJA1, cumulus expansion-related gene), delta-6 desaturase (FADS1, fatty acid metabolism-related gene), and delta-5 desaturase (FADS2) mRNA in cumulus cells were reduced by $50{\mu}M$ ALA treatment (p<0.05). Cleavage rate was enhanced in 25 and $50{\mu}M$ ALA groups (p<0.05), especially, treatment of $50{\mu}M$ ALA promoted early embryo develop to 4 and 8 cell stages (p<0.05). However, blastocyst formation and number of cells in blastocyst were not differ in 25 and $50{\mu}M$ ALA groups. Our findings show that ALA treatment during maturation could improve nuclear maturation, fertilization, and early embryo development through enhancing of cumulus expansion, however, fatty acid metabolism- and cumulus expansion-related genes were down-regulated. Therefore, addition of ALA during IVM of oocytes could improve fertilization and developmental competence, and further studies regarding with the mechanism of ALA metabolism are needed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.8
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• pp.541-548
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• 2019

In this paper, the required amount of heat for an anti-icing system of a Flush Air Data Sensing(FADS) system is predicted. For an efficient prediction during the early stage of a design process, a handbook method is used. A program of which inputs are flight conditions is developed to predict the required amount of heat. A CFD analysis is conducted to compute the water catch efficiency which is one of the core parameters used in the handbook method. Kriging method, one of well-known regression mothods, is utilized to construct a surface contour database to evaluate impingements of droplets. To predict the trajectories of droplets, the database of a flow field around the surface is built using Kriging method as well.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.12
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• pp.1957-1964
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• 2020

Objective: The aim of this study was to compare overfeeding performance, fatty acid composition, blood chemistry, enzymes and genes expression overfed Xupu and Landes geese. Methods: Sixty male Xupu geese (80 d) and Landes geese (80 d) were selected. After a period of one-week of pre-overfeeding, Xupu and Landes geese were overfed three meals of 550 and 350 g/d, respectively, of a high-carbohydrate diet in the first week of the overfeeding period. The next week, geese were given four meals of 1,200 and 850 g/d, respectively, over 8 to 14 d. Finally, geese were given five meals of 1,600 and 1,350 g/d, respectively, for the last two weeks. Results: After overfeeding for 28 d: Compared with Landes geese, Xupu geese liver weight and liver-to-body weight ratio decreased (p<0.05), while final weight, slaughter weight, total weight gain, abdominal fat weight, and feed-to-liver weight ratio increased (p<0.05). The levels of elaidic acid (C18:1t9), oleic acid (C18:1n-9), eicosenoic acid, and arachidonic acid in the liver of Xupu geese significantly increased (p<0.05), and the levels of myristic acid and stearic acid significantly decreased (p<0.05), while methyleicosanoate acid significantly increased (p<0.05). Xupu geese had higher plasma concentrations of triglyceride and very low density lipoprotein cholesterol (p<0.05), and decreased activities of alanine aminotransferase, aspartate aminotransferase, and lipase (LPS) (p<0.05). Landes geese had higher LPS activity (p<0.05), but lower cholinesterase activity (p<0.05) when compared with Xupu geese. The mRNA expression levels of fatty acid dehydrogenase (FADS) gene, elongase of long-chain fatty acid 1 (ELOVL1) gene, ELOVL5, and acyl-Co A: cholesterol acyltransferase 2 (ACAT2) gene were significantly upregulated (p<0.05) in Landes goose when compared with Xupu geese. Conclusion: This study demonstrates that the liver production performance of Landes geese was better than that of Xupu geese to some extent, which may be closely related to LPS activity, as well as the expression of FADS, ELOVL1, ELOVL5, and ACAT2.