• Composites Research
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• 제13권4호
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• pp.1-10
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• 2000

SiC가 강화된 금속복합재료는 기존의 금속재료에 비하여 비탄성계수와 비강도가 높기 때문에 자동차 및 항공산업에 많은 응용이 기대되고 있다. 금속복합재료의 파손기구는 적용된 하중에 의한 미시적 손상의 축적에 의해 많은 영향을 받기 때문에 금속복합재료의 광범위한 응용을 위해서는 금속복합재료가 반복 하중을 받을 때 미시적 파손기구를 이해하는 것이 대단히 중요하다. 따라서 본 연구에서는 SiCp/A356 금속복합재료의 미시적 손상 축적을 모니터링 하기 위하여 초음파와 음향방출기법을 적용하였다. 반복하중의 증가에 따라 초음파의 속도와 감쇠의 변화는 각 미시적 손상기구에 따라 3영역으로 나눌 수 있었다. 또한 각 영역에서 발생하는 AE 신호의 특징은 초음파의 속도 및 감쇠 변화와 비교, 분석되었다.

• Structural Engineering and Mechanics
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• 제36권4호
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• pp.463-479
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• 2010

Based on damage accumulation of multi-grid composite walls, a method of dynamic reliability estimations is proposed. The multi-grid composite wall is composed of edge frame beam, edge frame columns, grid beams, grid columns and filling blocks. The equations including stiffness, shear forces at filling blocks cracking and multi-grid composite walls yielding, ultimate displacement, and damage index are obtained through tests of 13 multi-grid composite wall specimens. Employing these equations in reliability calculations, procedures of dynamic reliability estimations based on damage accumulation of multi-grid composite walls subjected to random earthquake excitations are proposed. Finally the proposed method is applied to the typical composite wall specimen subjected to random earthquake excitations which can be specified by a finite number of input random variables. The dynamic reliability estimates, when filling blocks crack under earthquakes corresponding to 63% exceedance in 50 years and when the composite wall reach limit state under earthquakes corresponding to 2-3% exceedance in 50 years, are obtained using the proposed method by taking damage indexes as thresholds. The results from the proposed method which show good agreement with those from Monte-Carlo simulations demonstrate the proposed method is effective.

• Animal Bioscience
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• 제34권7호
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• pp.1089-1099
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• 2021

With the development of sequencing technology, numerous, long noncoding RNAs (lncRNAs) have been discovered and annotated. Increasing evidence has shown that lncRNAs play an essential role in regulating many biological and pathological processes, especially in cancer. However, there have been few studies on the roles of lncRNAs in livestock production. In animal products, meat quality and lean percentage are vital economic traits closely related to adipose tissue deposition. However, adipose tissue accumulation is also a pivotal contributor to obesity, diabetes, atherosclerosis, and many other diseases, as demonstrated by human studies. In livestock production, the mechanism by which lncRNAs regulate adipose tissue deposition is still unclear. In addition, the phenomenon that different animal species have different adipose tissue accumulation abilities is not well understood. In this review, we summarize the characteristics of lncRNAs and their four functional archetypes and review the current knowledge about lncRNA functions in adipose tissue deposition in livestock species. This review could provide theoretical significance to explore the functional mechanisms of lncRNAs in adipose tissue accumulation in animals.

• Journal of Ginseng Research
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• 제47권4호
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• pp.572-582
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• 2023

Background: Free fatty acid-induced lipotoxicity is considered to play an important role in pancreatic β-cell dysfunction. The effect of ginsenosides on palmitic acid-induced pancreatic beta-cells cell death and failure of glucose-stimulated secretion of insulin (GSIS) was evaluated in this study. Methods: Enzyme-linked immunosorbent assay kit for a rat insulin was used to quantify glucose-stimulated insulin secretion. Protein expression was examined by western blotting analysis. Nuclear condensation was measured by staining with Hoechst 33342 stain. Apoptotic cell death was assessed by staining with Annexin V. Oil Red O staining was used to measure lipid accumulation. Results: We screened ginsenosides to prevent palmitic acid-induced cell death and impairment of GSIS in INS-1 pancreatic β-cells and identified protopanaxadiol (PPD) as a potential therapeutic agent. The protection effect of PPD was likely due to a reduction in apoptosis and lipid accumulation. PPD attenuated the palmitic acid-induced increase in the levels of B-cell lymphoma-2-associated X/B-cell lymphoma 2, poly (ADP-ribose) polymerase and cleaved caspase-3. Moreover, PPD prevented palmitic acid-induced impairment of insulin secretion, which was accompanied by an increase in the activation of phosphatidylinositol 3-kinase, peroxisome proliferator-activated receptor γ, insulin receptor substrate-2, serine-threonine kinase, and pancreatic and duodenal homeobox-1. Conclusion: Our results suggest that the protective effect of PPD on lipotoxicity and lipid accumulation induced by palmitic acid in pancreatic β-cells.

• Asian-Australasian Journal of Animal Sciences
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• 제22권12호
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• pp.1686-1692
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• 2009

Garlic oil (GAR, Allium sativum L.) has been studied as a feed additive to improve animal production performance and decrease methane emission in ruminants. The present study was designed to determine the possible effect of GAR on fatty acid composition and accumulation in animal fat tissue using a cell model. 3T3-L1 preadipocytes at $2{\times}10^{4}\;mL^{-1}$ were seeded to 24-well plates and allowed to proliferate to reach confluence. The cells were then treated with media containing 0, 2.5, 5, 10, 20 and 40 $\mu{g}$ $mL^{-1}$ of GAR during the differentiation period for 8 days. Media containing dexamethasone, methyl-isobutylxanthine and insulin was applied during the first 2 days of the early differentiation period. On day 8 sub-sets of the wells were stained with oil red-O and the remaining cells were harvested for determination of glycerol-3-phosphate dehydrogenase [EC 1.1.1.8] (GPDH) activity (n = 6) and cellular fatty acid concentration (n = 6). It was found that supplementation of GAR increased (p<0.05) the ratio of monounsaturated fatty acids/saturated fatty acids in the adipocytes and showed inhibitory effect (p<0.05) on the post-confluent proliferation. With relative low dosage, GAR (5-20 $\mu{g}$ $mL^{-1}$) increased (p<0.05) the GPDH activity without affecting the cellular fatty acid concentration, while a high dosage (40 $\mu{g}$ $mL^{-1}$) inhibited (p<0.05) fatty acid accumulation and decreased GPDH activity. Supplementation of GAR had an effect on cell post-confluent proliferation, differentiation and fatty acid accumulation. However, the effect may be diverse and depends on the dose applied.

• 한국초지조사료학회지
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• 제19권1호
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• pp.81-88
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• 1999

본 시험은 질소비료의 다용(多用)이 사초내의 질산염 함량, 강우에 의한 사초내의 질산염 함량, 그리고 하루 중 사초내의 질산염 함량의 차이를 조사하여 반추가축의 질산염 중독 발생 예방과 적정 질소시비수준을 구명하기 위하여 수단그라스계 교잡종 중 Xtragraze II 1번초를 공시하여 1995년 6월부터 9월까지 익산대학 동물사육장 시험포에서 실시하였다. 시비수준은 ha당 연간 질소 200kg, 400kg 및 600kg으로 하고, 인산과 칼리비료는 200kg씩 사용하였으며 얻어진 결과는 다음과 같다. 질산태질소 함량은 생육시기의 진전에 따라 감소하였는데, 200kg구에서는 신장기초까지, 그리고 400kg 이상에서는 전생육기간 동안 중독위험수준을 초과하였다. 강우 후 사초의 질산태질소 함량은 성장기에는 일시적으로 증가하는 경향이 있지만, 생육말기나 출수기 이후에는 거의 영향이 없었다. 사초의 하루 중 질산태질소 함량은 오전이 오후보다 비교적 더 높은 경향이었다. 질산염중독으로부터 비교적 안전한 질소시비수준은 $200kg{\cdot}N/ha/year$ 이하로 나타났다.

• 공업화학
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• 제24권2호
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• pp.155-160
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• 2013

미세조류의 지질축적을 증가시키는 것에 대한 돌연변이 생성 및 분리에 관한 연구는 바이오디젤 산업에 중요한 문제이다. 본 연구에서는, 광합성 미세조류인 Nannochloropsis oculata (N. oculata)를 이용하여 자외선(UV-B 타입)으로 돌연변이를 유도하였다. 그 결과 콜로니가 생성되었고, 그 이후에 f/2 액체배지와 고체배지에 배양하였다. 몇 주간 배양후, 변화된 세포성장률과 세포건조중량, 그리고 몇 가지 중요한 세포 구성 요소를 조사하였다. 수천 개의 변이주 중 두 개의 변이주가 야생균주에 비해서 증가된 세포성장과 높은 지질 축적을 보였다. 또한 증가된 세포성장률과 함께 단백질 과발현 현상이 관찰되었다. 그러나 돌연변이주의 클로로필 생합성의 감소를 확인 할 수 있었다.

• 대한한의학원전학회지
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• 제12권2호
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• pp.166-174
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• 1999

Meridians are often defined as passway of Ki and Blood or something that can control funtions of the body. It is true but I think meridians have something more than that. Meridians are not just passway of Ki and Blood, rather they receive Ki from outside and transform it into Essence-Ki(精氣). If we draw a line in a body, we have Chang-Pu inside and meridians outside. Chang-Pu whim is inside our body hold Essence-Ki and manipulate it. These Chang-Pu also have variation of Ki accumulation-Tai-Yang, Soyang, T'ae$\breve{u}$m, Soum. Nevertheless, their gradients are not great so Ki flow among them are not great either. If there are much Ki flow in our body there will be much Ki consumption resulting in exhaustion of Essence-Ki, which is very hard to acquire. Therefore Chang-Pu keeps less gradient by not moving Ki a lot to preserve Essence-Ki. Chang-Pu, inside, are suitable for storing Ki while meridians, outside, are for producing Ki. Meridinas have great difference in Ki accumulation so there are great flow of Ki. This nature is suitable for producing Ki. For example, roots and limbs of a tree don't have much gradient in Ki. They are concentrated and their shape are not very distinct. On the other hand, leaves are wide and it's easy to tell front from back. It means their Ki gradient is great and their Ki flow is also great. Therefore they suitable for producing Ki. Just like this, meridians in our body are suitable for producing Ki. Areas that meridians cover are much wider than that of Chang-Pu. Four limbs and surface of our body are very distinctive. Ulnar side is high in Ki accumulation but is small in volume so it's better to store Ki there. Radial side is low in Ki accumulation but big in volume so it's better to receive and consume Ki there. Meridians are deeply involved in producing and storing Ki.

• 한국토양비료학회지
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• 제45권4호
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• pp.572-581
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• 2012

In this study, we compared growth pattern, floc yield, Exo-polysaccharides (EPS) production, Poly-${\beta}$-hydroxybutyrate (PHB) accumulation, resistance to osmotic and acid stress in Methylobacterium strains CBMB20, CBMB27, CBMB35, and CBMB110. Modified high C:N ratio medium denoted as HCN-AMS medium was used with a C:N ratio of 30:1. The HCN-AMS medium favored increased growth in all the studied strains. All Methylobacterium strains tested positive for EPS production and showed positive fluorescence with calcoflour stain. Elevated levels of EPS production from 4.2 to 75.0% was observed in HCN-AMS medium. Accumulation of PHB in HCN-AMS medium increased by 3.8, 36.7, and 12.0% in strains CBMB27, CBMB35, and CBMB110 respectively. Among the abiotic stresses, osmotic stress-induced growth inhibition of Methylobacterium strains was found to be lowered when grown in HCN-AMS medium. Likewise, growth inhibition due to acid stress at pH 5.0 was lower for strains grown in HCN-AMS medium compared to growth in AMS medium. Enhanced survivability under stress conditions may be attributed to the high EPS and PHB production at increased carbon concentration in the growth medium.

• 한국미생물·생명공학회지
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• 제10권2호
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• pp.87-93
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• 1982

Mucor plumbeus FRI 0007 균주의 배양조건에 따른 균체생산량 및 지방질의 생산량을 검토한 결과 온도는 37$^{\circ}C$, pH3.5에서 정치배양 하는 것이 최적조건이며, 25일간 배양했을때 균체량은 2.39g/50$m\ell$, 지방질의 함량은 50.73% 이었다. 균체량과 지방질의 함량은 온도가 증가할수록, pH가 낮을수록 증가하였으나 진탕배양의 경우 균체량은 감소하나 지방질의 함량은 증가되었다. 트리-글리세리드의 함량은 pH가 낮을때, 그리고 진탕배양을 했을때 그 함량이 높았다. 지방산의 조성은 온도, 질소원와 종류 및 진탕에 의한 영향을 받았으며 온도가 낮을때 그리고 진탕을 했을때 포화도가 낮았다. 지방질을 구성하고 있는 모노-글리세리드와 디-글리세리드는 팔미트산과 올레산으로 트리-글리세리드는 주로 팔미트산, 올레산 및 리놀레산으로 결합되어 있으며 포화도는 모노-글리세리드가 가장 높았다.