• Journal of Marine Bioscience and Biotechnology
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• v.1 no.2
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• pp.63-70
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• 2006

Natural product compounds are the source of numerous therapeutic agents. The marine environment produces natural products from a variety of structural classes exhibiting activity against numerous disease targets including anticancer agents. Among these, pectenotoxin-2 (PTX-2), which was first identified as a cytotoxic entity in marine sponges, which depolymerizes actin filaments, was found to be highly effective and more potent to activate an intrinsic pathway of apoptosis in p53-deficient tumor cells compared to those with functional p53 both in vitro and in vivo. However, the anti-proliferative mechanism of the compound at non-cytotoxic concentrations has not yet been explored. In the current study, we sought to investigate anti-proliferation and apoptosis of PTX-2 against U937 human leukemic cells and its underlying molecular mechanism. Exposure of U937 cells to PTX-2 resulted in growth inhibition and induction of apoptosis in dose- and time-dependent manner as measured by MTT assay, fluorescent microscopy and flow cytometric analysis. The anti-proliferative effect of PTX-2 was associated with a marked increase in the expression of cyclin-dependent kinase p21 (WAF1/CIP1) mRNA which was tumor suppressor p53-independent. The increase in apoptosis was connected with a time-dependent down-regulation of anti-apoptotic Bcl-XL and inhibitor of apoptosis proteins (IAPs) family such as XIAP and cIAP-2. Though additional studies are needed, these findings suggested that PTX-2-induced inhibition of U937 cells was associated with the induction of apoptotic cell death and the results provided important new insights into the possible molecular mechanisms of the anti-cancer activity of PTX-2.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.05a
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• pp.14-14
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• 2003

Silicon carbide (SiC)는 높은 power 영역과 높은 온도영역에서도 작동 가능한 우수한 반도체 물질이다. 또한 우수한 열적 화학적, 안정성을 가지고 있어 가흑한 조건에서의 소자로써도 사용 가능하다. 현재 SiC 적용분야로는 우수한 전기적, 기계적 성질을 이용한 미세소자(MEMS)와 GaN 와 거의 유사한 격자상수를 가지는 것을 이용한 GaN epitaxial 성장의 기판으로도 사용되어진다. 그러나 SiC 는 기존의 습식식각 용매에 대해 화학적 안정성을 가지고 있기 때문에 전자소자의 제작에 있어서 플라즈마를 이용한 건식식각의 중요성이 대두되어지고 있다. 소자제작에 있어 이러한 건식식각시 식각 단면의 제어, 이온에 의한 낮은 손상 정도, 매끄러운 식각 표면, 그리고 고속의 식각 속도둥이 요구되어진다. 본 실험에서는 식각 속도의 증가와 수직한 식각 단면둥을 획득하기 위하여 SF6 플라즈마에서 Source power, dc bias voltage, 그리고 외부에서 인가되는 자속의 세기를 변화시쳐가며 식각 속도, 식각 마스크와의 식각 션택비, 식각 단면둥과 같은 SiC 의 식각 특성을 관찰하였다. 식각 후 식각 단면은 주사전자 현미경(SEM)을 통해 관찰하였다. 본 실험에서의 가장 높은 식각 속도는 분당 1850n 로써 이때의 공정조건은 1400W 의 inductive power, -600V 의 dc bias voltage, 20G 의 외부자속 세기이었다. 또한, 높은 inductive power 조건과 낮은 dc bias voltage 조건에서 Cu는 $SF_6$ 플라즈마 내에서 식각부산물의 증착으로 인해 SiC 와 무한대의 식각선택비를 보였다. 이러한 Cu 마스크를 사용한 SiC 의 식각에서는 식각 후 수직한 식각 단변을 관찰할 수 있었다. 것올 알 수 있다. 따라서, 기존의 pve 보다 세라믹 기판의 경우가 수분 흡수율이 높아 더 오랫동안 전류를 흐르게 하여 방식성이 개선된 것으로 판단된다.을 통해 경도가 증가한 시편의 경우 석출상의 크기가 5nm 이하로 매우 작고 대체로 기지와 연속적인 계면을 형성하나, 열처리가 진행될수록 석 출상의 크기가 커지고 임계크기 이상에 이르면 연속적인 계면은 거의 발견되지 않고, 대부 분 불연속적이고 확연한 계면을 형성함을 관찰 할 수 있었다. 알루미나(${\alpha}-Al_2O_3$) 기판 위에 증착한 $(Ti_{1-x}AI_{x})N$ 피막은 마찬가지로 (200) 우선 방위를 나타내었으나, 그 입자의 크기가 수십 nm로 고속도강위에 증착한 피막에 비해 상당히 크게 형성되었다. 또한 열처리 후에 AIN의 석출이 진행됨에도 불구하고 경도 증가는 나타나지 않고, 열처리가 진행됨에 따라 경도가 감소하는 양상만을 나타내었다. 결국 $(Ti_{1-x}AI_{x})N$ 피막이 열처리 전후에 보아는 기계적 특성의 변화 양상은 열역학적으로 안정한 Wurzite-AlN의 석출에 따른 것으로 AlN 석출상의 크기에 의존하며, 또한 이러한 영향은 $(Ti_{1-x}AI_{x})N$ 피막에 존재하는 AI의 함량이 높고, 초기에 증착된 막의 업자 크기가 작을 수록 클 것으로 여겨진다. 그리고 환경의 의미의 차이에 따라 경관의 미학적 평가가 달라진 것으로 나타났다.corner$적 의도에 의한 경관구성의 일면을 확인할수 있지만 엄밀히 생각하여 보면 이러한 예의 경우도 최락의 총체적인 외형은 마찬가지로 $\ulcorner$순응$\lrcorner$의 범위를 벗어나지 않는다. 그렇기 때문에

• Geophysics and Geophysical Exploration
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• v.23 no.1
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• pp.1-12
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• 2020

In the development of geodynamic structures such as subduction and rift zones, a weakening mechanism is essential for localized weak zone formation in the lithosphere. Shear heating, a weakening mechanism, generates short-wavelength temperature elevation in the lithosphere; the increased temperature can reduce lithospheric strength and promote its breakup. A two-dimensional elastoplastic extensional basin model was used to conduct benchmarking based on previous numerical simulation studies to quantitatively analyze shear heating. The amount of shear heating was investigated by controlling the yield strength, extensional velocity, and strain- and temperature-dependent weakening. In the absence of the weakening mechanism, the higher yield strength and extensional velocity led to more vigorous shear heating. The reference model with a 100-MPa yield strength and 2-cm/year extension showed a temperature increase of ~ 50 K when the bulk extension was 20 km (i.e., 0.025 strain). However, in the yield-strength weakening mechanism, depending on the plastic strain and temperature, more efficient weakening induced stronger shear heating, which indicates positive feedback between the weakening mechanism and the shear heating. The rate of shear heating rapidly increased at the initial stage of deformation, and the rate decreased by 80% as the lithosphere weakened. This suggests that shear heating with the weakening mechanism can significantly influence the strength of relatively undamaged lithosphere.

• Korean Journal of Plant Resources
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• v.34 no.4
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• pp.278-286
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• 2021

Efficient in vitro regeneration system is essential for the successful crop breeding of soybean (Glycine max (L.) Merr.) using the new biotechnology. The genotype of donor plants strongly influences the establishment of tissue culture system. Therefore, the screening of genotypes with excellent tissue culture ability is very important for soybean genetic improvement. In this study, we report the tissue culture efficiency of 21 soybean cultivars belong to Korean soybean core-collection and two foreign cultivars (Jack and Maverick). The Kwangan, Anpyeong and Seonam are share close genetic relationship in 21 cultivars and these three cultivars were observed the high frequency of germination and regeneration. Furthermore, the high tissue culture abilities were also observed in the Williams 82 used in reference genome sequencing and the two foreign cultivars. The transformation of pBAtc:tRNA with bar gene was performed by Agrobacterium tumefaciens in the cultivars with high tissue culture ability. Transformation of the bar gene was identified by PCR analysis in Kwangan, Pungwon, Seonam, and Maverick. Our results provide useful information for the breeding of various soybean cultivars by plant biotechnology such as, genome editing.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.6
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• pp.96-110
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• 2018

As the development of ICT has made it easier to collect various traffic information, research on creating new traffic attributes is drawing attention. Estimation and forecasts of demand and traffic volume are one of the main indicators that are essential to traffic operation, assuming that the traffic pattern at a particular node or link is repeated. Traditionally, a survey method was used to demonstrate this similarity on trip behavior. However, the method was limited to achieving high accuracy with high costs and responses that relied on the respondents' memory. Recently, as traffic data has become easier to gather through ETC system, smart card, studies are performed to identify the regularity of trip in various ways. In, this study, route-level trip data collected in Daegu metropolitan city were analyzed to confirm that individual traveler forms a spatially similar trip chain over several days. For this purpose, we newly define the concept of spatial trip regularity and assess the spatial difference between daily trip chains using the sequence alignment algorithm, Dynamic Time Warping. In addition, we will discuss the applications as the indicators of fixed traffic demand and transportation services.

• Korean Journal of Plant Resources
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• v.34 no.5
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• pp.411-419
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• 2021

In this study, we investigated in vitro immune-enhancing and anti-obesity activity of Abelmoschus manihot roots (AMR) in mouse macrophage RAW264.7 cells and mouse adipocytes 3T3-L1 cells. AMR increased the production of immunostimulatory factors such as nitric oxide (NO), inducible nitric oxide synthase (iNOS), interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in RAW264.7 cells. The inhibition of toll like receptor (TLR) 2 and 4 blocked AMR-mediated production of immunostimulatory factors in RAW264.7 cells. In addition, the inhibition of mitogen-activated protein kinases (MAPKs) signaling pathway reduced AMR-mediated production of immunostimulatory factors. From these results, AMR is considered to have immune-enhancing activity through TLR2/4-mediated activation of MAPKs signaling pathway. In addition, AMR inhibited lipid accumulation and reduced the protein level such as CCAAT enhancer-binding protein alpha (CEBPα), peroxisome proliferator-activated receptor gamma (PPARγ), perilipin-1, adiponectin and fatty acid binding protein 4 (FABP4) associated with lipid accumulation in 3T3-L1 cells, indicating that AMR may have anti-obesity activity. Based on these results, AMR is expected to be used as a potential functional agent for immune enhancement and anti-obesity.

• Journal of Life Science
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• v.31 no.2
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• pp.192-198
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• 2021

Red yeast rice has been extensively used as food and traditional medicine for thousands of years in East Asian countries. It is produced by the fermentation of a particular yeast (in general, Monascus purpureus) as rice and various cereals (barley, soybean, etc.). Monascus sp. produces many secondary metabolites during its growth, including pigments, monacolins, and γ-aminobutyric acid. Some metabolites―specifically, monacolin K, γ-aminobutyric acid, dimerumic acid, and monascus pigments―have been reported to lower cholesterol and blood pressure while showing anti-obesity effects. In this study, we investigated the anti-obesity effect of ethanol extract from red yeast barley (RYB) fermented with Monascus sp. BHN-MK 2 on 3T3-L1 cells. The anti-obesity effects of RYB extract were examined: its lipid accumulation inhibitory effect was tested by Oil Red O staining, and obesity-related mRNA expression levels were tested by real-time RT-PCR in MDI stimulated 3T3-L1 cells. The intracellular lipid content of MDI-stimulated 3T3-L1 cells decreased significantly to 5.04%, 12.24%, and 23.52% in response to 200, 400, and 800 ㎍/ml RYB, respectively. Moreovers, we evaluated that RYB extract significantly downregulated the expression of C/EBPα, SREBP-1, and PPAR-γ gene in a dose-dependent manner. As a result, red yeast barley ethanol extracts exerted the strongest anti-obesity effects. Also, the results indicate that red yeast barley could be used as a functional anti-obesity food material.

• Journal of Korea Society of Industrial Information Systems
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• v.25 no.6
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• pp.25-32
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• 2020

The seed, the most basic component, is an important factor in increasing production and efficiency in agriculture. Seeds with superior genes can be expected to improve agricultural productivity, crop survival, and reproduction. Currently, however, screening of superior seeds depends mostly on manual work, which requires a lot of time and manpower. In this paper, we propose a system that can extract the characteristics of seed phenotypes by using computer image processing technology, so that even a small number of people and a short period of time are needed to extract the characteristics of seeds. The proposed system detects individual seeds from images containing large quantities of seeds, and extracts and stores various characteristics such as representative colors, area, perimeter and roundness for each individual seed. Due to the regularity of input images, the accuracy of individual seed extraction in the proposed system is 99.12% for soybean seeds and 99.76% for rice seeds. The extracted data will be used as basic data for various data analyses that reflect the opinions of experts in the future, and will be used as basic data to determine the expressive nature of each seed.

• Journal of the Korean Regional Science Association
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• v.36 no.4
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• pp.3-23
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• 2020

This study aims to conceptualize the settlement inclusivity for overcoming social exclusion and the decline in quality of life of older people and to examine its effects on their mental health. The concept of the settlement inclusivity for older people focuses on the immediate environment around the place where they live. We proposed two domains for the conceptual framework; social domain that provides opportunities for community cohesion; spatial domain that provides security of residential area and access to basic services within walking distance. The social domain was represented by participation and interdependence, while the spatial domain by security and accessibility in the settlement inclusivity. Zero-inflated negative binomial regression model was constructed with 2017 National Survey of Older Koreans data to analyze the factors influencing depressive symptoms of older adults. The empirical results demonstrate that increased level of neighborhood network and social participation is associated with a decrease in the number of depressive symptoms. In addition, higher satisfaction in neighborhood environment and good accessibility to public transport/stores are associated with fewer depressive symptoms. Finally, housing condition and home ownership have a moderating effect on the relationship between social network/participation and depressive symptoms level, whereas they have no direct effects on depressive symptoms. This study demonstrates multi-dimensionally and mutually significant associations between settlement inclusivity and depressive symptoms for older people providing implications for urban planning and policies to improve mental well-being of older population.

• New Physics: Sae Mulli
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• v.68 no.12
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• pp.1302-1307
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• 2018

The crystallographic, electrical and magnetic behaviors of magnetite powder in the vicinity of its Verwey transition were investigated in this study. Magnetite was prepared by synthesizing a nanoparticle precursor and then annealing it at $800^{\circ}C$ for 1 h under a dynamic vacuum. Crystallographic and morphology analyses were done by using scanning electron microscope (SEM) and X-ray diffraction (XRD). The electrical and the magnetic properties were examined by using $M{\ddot{o}}ssbauer$ spectroscopy, vibrating sample magnetometer (VSM) and resistivity measurement. Both the magnetic moment and the resistivity showed discontinuous changes at the Verwey transition temperature ($T_V$). The temperature dependence of magnetic anisotropy constant showed a monotonic decrease with increasing temperature, with slight dip near $T_V$. $M{\ddot{o}}ssbauer$ spectra showed the superposition of two sextets, one from the tetrahedral (A) and the other from the octahedral (B) sites. The results revealed that identical charge states existed in the B site at temperatures both above and below $T_V$. A coordination crossover resulted in a transition from an inverse to a normal spinel at or close to $T_V$.