• 한국재료학회지
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• 제4권3호
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• pp.334-338
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• 1994

Pb-Sn eutectic bulk specimens을 thermal cycling동안 electronic package의 땜납이 격게되는 변형 조건 즉 $10^{-3}-10^{-5}$/s정도의 낮은 frequency와 0.2-1%정도의 적당한 strain range에서 피로파괴 실험을 했을때, grain boundary sliding과 관련하여 임계면을 따라 일어나는 균열이 5단계에 의해 묘사될 수 있다는 것을 보였음.

• 대한한의학회지
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• 제23권4호
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• pp.113-124
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• 2002

Objects: This research was conducted to investigate the protective effect of Bupleuri Radix against ischemic damage using PC12 cells and global ischemia in gerbils, Methods: To observe the protective effect of Bupleuri Radixon ischemic damage, viability and changes in activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase and production of malondialdehyde (MDA) were observed after treating PC12 cells with Bupleuri Radix during ischemic damage. Gerbils were divided into three groups: a normal group, a 5-minute two-vessel occlusion (2VO) group and a Bupleun Radix administered group after 2VO. The CCAs were occluded by microclip for 5 minutes, Bupleuri Radix was administered orally for 7 days after 2VO. Histological analysis was performed on the 7th day. For histological analysis, the brain tissue was stained with 1 % of cresyl violet solution. Results: 1. Bupleuri Radix has a protective effect against ischemia in the CA1 area of the gerbil's hippocampus 7 days after 5-minute occlusion. 2. In the hypoxia/reperfusion model using PC12 cells, the Bupleuri Radix has a protective effect against ischemia in the dose of 0.2{\;}\mu\textrm{g}/ml,2{\;}\mu\textrm{g}/ml{\;}and{\;} 20{\;}\mu\textrm{g}/ml$. 3. Bupleuri Radix increased the activities of glutathione peroxidase and catalase. 4. The increased activity of superoxidedismutase (SOD) by ischemic damage might have been induced as an act of self-protection. This study suggests that Bupleuri Radix has some neuroprotective effect against neuronal damage following cerebral ischemia in vivo with a widely used experimental model of cerebral ischemia in Mongolian gerbils. Bupleuri Radix also has protective effect on a hypoxia/reperfusion cell culture model using PC12 cells. Conclusions: Bupleuri Radix has protective effect against ischemic brain damage during the early stages of ischemia.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1216-1222
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• 2009

Ecological Engineering (EE) refers to all sustainable engineering that can reduce damage to ecosystems and that adopts ecology as a base and safety as an orientation in order to implement conservation of biodiversity and sustainable development. In short, EE attempts to safeguard the ecological environment while any essential construction projects proceed. EE encompasses many fields, including construction skills, ecosystem preservation, landscape, and even related cultures and so on. Such variety results in greater complexity of construction, and, consequently, indirectly increases the difficulty of construction quality control. The objective of our research is to explore a promising model for EE via an extensive literature survey. This model includes three principal stages: plan-design, construction, and maintenance, along with individual accompanying phases concerned with quality control and vital management. In this article, a river restoration example is adopted to describe in detail the critical points of quality control in the three stages (plan-design, construction, and maintenance) of the construction life cycle. This study proposes an integrated structure for quality management of EE to guarantee its quality and to enhance its core applications in order to achieve long-lasting preservation of the environment.

• 한국응용곤충학회지
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• 제43권3호
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• pp.249-255
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• 2004

호남지역 콩 포장에서 톱다리개미허리노린재의 발생소장, 콩 피해 및 약제방제 효과를 검토하였다. 톱다리개미허리노린재의 발생은 콩 파종시기 및 연차간에 차이가 있었다. 톱다리개미허리노린재의 발생최성기는 5월 하순경 파종은 8월 하순에, 6월 중순경 파종은 9월 중순 이었고, 파종기가 동일하더라도 연차간 기상조건에 따른 중 생육상의 차이로 톱다리개미허리노린재의 발생최성기 차이가 있었다. 톱다리개미허리노린재에 의한 콩 흡즙 피해 면적을이 증가하면 발아율이 현저하게 낮아졌으며, 특히, 콩 피해면적율이 $50\%$ 이상 되면 발아율이 $2\%$로 매우 낮았다. 톱다리개미허리노린재에 대한 약제방제효과는 콩 생육단계중 $R_4$(착협성기)+ $R_5$(립비대기)+ $R_6$(립비대성기)에 3회 처리시 $91\%$의 방제효과로 가장 높았다.

• Animal Bioscience
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• 제36권7호
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• pp.1022-1033
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• 2023

Objective: p66Shc, a 66 kDa protein isoform encoded by the proto-oncogene SHC, is an essential intracellular redox homeostasis regulatory enzyme that is involved in the regulation of cellular oxidative stress, apoptosis induction and the occurrence of multiple age-related diseases. This study investigated the expression profile and functional characteristics of p66Shc during preimplantation embryo development in sheep. Methods: The expression pattern of p66Shc during preimplantation embryo development in sheep at the mRNA and protein levels were studied by quantitative real-time polymerase chain reaction (RT-qPCR) and immunofluorescence staining. The effect of p66Shc knockdown on the developmental potential were evaluated by cleavage rate, morula rate and blastocyst rate. The effect of p66Shc deficiency on reactive oxygen species (ROS) production, DNA oxidative damage and the expression of antioxidant enzymes (e.g., catalase and manganese superoxide dismutase [MnSOD]) were also investigated by immunofluorescence staining. Results: Our results showed that p66Shc mRNA and protein were expressed in all stages of sheep early embryos and that p66Shc mRNA was significantly downregulated in the 4-to 8-cell stage (p<0.05) and significantly upregulated in the morula and blastocyst stages after embryonic genome activation (EGA) (p<0.05). Immunofluorescence staining showed that the p66Shc protein was mainly located in the peripheral region of the blastomere cytoplasm at different stages of preimplantation embryonic development. Notably, serine (Ser36)-phosphorylated p66Shc localized only in the cytoplasm during the 2- to 8-cell stage prior to EGA, while phosphorylated (Ser36) p66Shc localized not only in the cytoplasm but also predominantly in the nucleus after EGA. RNAi-mediated silencing of p66Shc via microinjection of p66Shc siRNA into sheep zygotes resulted in significant decreases in p66Shc mRNA and protein levels (p<0.05). Knockdown of p66Shc resulted in significant declines in the levels of intracellular ROS (p<0.05) and the DNA damage marker 8-hydroxy2'-deoxyguanosine (p<0.05), markedly increased MnSOD levels (p<0.05) and resulted in a tendency to develop to the morula stage. Conclusion: These results indicate that p66Shc is involved in the metabolic regulation of ROS production and DNA oxidative damage during sheep early embryonic development.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.561-568
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• 2003

The protection of adjacent structures in urban excavation has been an important issue. But the research on the interaction between ground movements and adjacent structure has been scarce, therefore this study was necessitated. Current design practice for the prediction of excavation-induced ground movements heavily rely on empirical method. In this study, damage levels of brick building are examined closely by means of angular distortion, deflection ratio, horizontal strain. The results of numerical analysis indicated that the movement of actual building was 60∼65% of the ground movement, while angular distortion was 45∼65%. Also numerical analysis for the assessment of brick building can be applied to the building protection at various construction stages.

• 한국농공학회논문집
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• 제46권5호
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• pp.89-98
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• 2004

The amount of rice yield reduction due to inundation should be estimated to analyse economic efficiency of the farmland drainage improvement projects because those projects are generally promoted to mitigate flood inundation damage to rice in Korea. Estimation of rice yield reduction will also provide information on the flood risk performance to farmers. This study presented the relationships between inundated durations and rice yield reduction rates for different rice growth stages from the observed data collected from 1966 to 2000 in Korea, and developed the rice yield reduction estimation model (RYREM). RYREM was applied to the test watershed for estimating the rice yield reduction rates and the amount of expected average annual rice yield reduction by the rainfalls with 48 hours duration, 10, 20, 50, 100, 200 years return periods.

• Computers and Concrete
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• 제4권2호
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• pp.101-117
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• 2007

A new model predicting the nonlinear basic creep behaviour of concrete structures subjected to high multi-axial stresses is proposed. It combines a model based on the thermodynamic framework of the elasto-plastic continuum damage theory for time-independent material behaviour and a rheological model describing phenomenologically the long-term delayed deformation. Strength increase due to ageing is regarded. The general 3D solution for the creep theory is derived from a rate-type form of the uniaxial formulation by the assumption of associated creep flow and a theorem of energy equivalence. The model is able to reproduce linear primary creep as well as secondary and tertiary creep stages under high compressive stresses. For concrete in tension a simple viscoelastic formulation is applied. The material law is then incorporated into a finite element solution procedure for analysis of reinforced concrete structures. Numerical examples of uniaxial creep tests and concrete members show excellent agreement with experimental results.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2005년도 추계학술발표대회 개요집
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• pp.73-75
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• 2005

The objective of this study is to estimate the feasibility of X-ray diffraction method application for fatigue life assessment of the high-temperature pipeline steel such as main steam pipe, reheater pipe and header etc. in power plant. In this study, X-ray diffraction tests using various types of specimen simulated low cycle fatigue damage were performed in order to analyze fatigue properties when fatigue damage conditions become various stages such as 1/4, 1/2 and 3/4 of fatigue life, respectively. As a result of X-ray diffraction tests for specimens simulated fatigue damages, we conformed that the variation of the full width at half maximum intensity decreased in proportion to the increase of fatigue life ratio.

• 대한두개안면성형외과학회지
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• 제20권4호
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• pp.246-250
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• 2019

Recently, there is a growing interest of hyperbaric oxygen therapy in many fields of medicine. We had a 43-year-old female patient presented with severe necrosis of the nose, philtrum, and upper lip due to retrograde arterial occlusion after nasolabial fold hyaluronic acid filler injection. Our patient went through 43 sessions of systemic hyperbaric oxygen therapy from December 2, 2017 to January 18, 2018. We administered 2.8 atmosphere absolute (ATA) for 135 minutes in the first session and the remaining sessions consisted of 2.0 ATA for 110 minutes. In reporting this case, we wish to provide a warning regarding the latent risk of filler injections and share our experience about minimizing soft tissue damage in the early stages with systemic hyperbaric oxygen therapy.