• Biomedical Science Letters
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• v.30 no.3
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• pp.113-122
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• 2024

In this study, we aimed to investigate the anti-cancer effects of the Pandanus tectorius extract on AGS cells. P. tectorius, commonly known as hala or screw pine, is a tropical plant traditionally used for its medicinal properties, including anti-inflammatory and antioxidant properties. Here, effects of the P. tectorius extract on cell proliferation, migration, and gene expression were evaluated using various assays, including the water-soluble tetrazolium salt (WST)-1, wound healing, migration, and western blotting assays. WST-1 assay revealed a significant dose- and time-dependent decrease in cell viability, with higher concentrations of the extract resulting in more pronounced viability inhibition. Wound healing and migration assays revealed that the P. tectorius extract effectively hindered cell migration, as the treated cells showed considerably slower wound closure and reduced migration than the control cells. Molecular analysis revealed that the extract significantly downregulated the expression levels of key oncogenic proteins, genes, and components of the Notch signaling pathway. Western blotting confirmed the substantial reduction in the marker protein levels in treated cells. These findings suggest that P. tectorius extract exerts its anti-cancer effects by inhibiting multiple signaling pathways crucial for cancer cell proliferation, migration, and survival. Overall, this study highlights the potential of P. tectorius extract as a therapeutic agent for gastric cancer treatment.

• Journal of the Korean Geographical Society
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• v.43 no.6
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• pp.894-913
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• 2008

This study examines scale issues in the contemporary feminist migration literature. Scale appears as important, yet poorly understood concept in this field of study. The increasing attention to the feminization of migration requires not only gendered, but also scalar-sensitive approaches. Feminists criticize the conventional approach to the migration as a gender-blind approach that privileges national scale around which migration processes are organized. Claiming multiscalar and interscalar analyses, they propose investigations ranging from macro to micro processes which include globalized gendered division of labor, transnational family networks, and reproduction which takes place in and through the bodies and homes of migrant women. The migrant women, the major actors in recent transnational migration, cross various borders: the national boundaries and the public and private divides, in particular. This crossover can unsettle patriarchal gender relations which have been established based on the physical and symbolic division of nation-states and public/private spheres. Blurring these divisions accompanies social construction of various scales. The transnational family networks of migrant women, for example, show the construction of a transnational scale by migrant women as well as globalization from below. This paper points out misunderstandings of scale in the feminist migration literature and attempts to fill the gaps by introducing the meanings and implications of scales developed mostly by feminist geographers. In so doing, it promotes the interdisciplinary communication.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.5 no.2
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• pp.24-30
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• 1999

The migration mechanism of trace elements, Pb, Cd, Cu, Zn and Sn from brass food-contact utensiles was investigated. The migration of metals from brass was affected by the migration temperature (30, 60, 80 and $95^{\circ}C$), the simulant pH (2.5, 4.3, 6.0 and 7.0) and the migration time (30, 90, 180 and 360 min.). The amount of Pb migration was maximum at $95^{\circ}C$ with pH 2.5. This study indicated that the equilibrium of Pb migration was reached at 180 minutes. The mechanism of Pb migration was investigated with Scanning Electron Microscope (SEM) and Electron Probe Micro Analyzer (EPMA). To correlate the relations between the migration and the content of Pb in brass samples, ten brass samples having known content of Pb (the quantities of Pb in brass ; 0, 0.02, 0.09, 0.1, 0.2, 0.5, 0.9, 1.4, 5.4 and 9.2% (w/w)) were tested in the following conditions, 4% acetic acid, $95^{\circ}C$ and 30 minutes. The result represented that content of Pb in brass samples must be below 0.2% (w/w) to satisfy the 1.0 ppm (as Pb) of Korea Food Code.

• Journal of Embryo Transfer
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• v.13 no.3
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• pp.301-312
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• 1998

To efficiently separate a protein stimulating sperm swim-up migration and movement from follicular proteins, the effect of paper chromatography and liquid chromatography with reverse phase column and superose column on protein separation was examined. And the results obtained were as follows; 1. The band component that was separated with paper chromatography stimulated sperm migration and movement depending on its additional levels. Especially, band I component significantly increased sperm migration. But, all components of bands 1, 2 and 3 showed lower sperm migration and movement, compared to follicular fluid at the same additional level. 2. Among the components separated from follicular protein of 2~5mm follicles with reverse phase column ($\mu$RPC), components at retention time (RT) of 3.33, 7.00, 13.87, and 16.6A minutes stimulated sperm migration within a limited range. 3. All components separated from follicular protein of 10mm follicles with $\mu$RPC column didn't stimulate sperm migration and movement. 4. Among the components separated from follicular protein of 2~5m follicles with superose column, components at retention volume (RV) of 1.35 and 0.82 ml significantly stimulated sperm migration and movement. In conclusion, protein components stimulating sperm migration and movement were efficiently separated with superose column in Smart system. Especially, components of RV 1.35 and RV0.82 stimulated sperm swim-up separation.

• Geophysics and Geophysical Exploration
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• v.19 no.2
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• pp.76-83
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• 2016

Migration image can be distorted due to reflected waves in the source and receiver wavefields when discontinuities of input velocity model exist in seismic imaging. To remove reflected waves coming from layer interfaces, it is a common practice to smooth the velocity model for migration. If the velocity model is smoothed, however, the subsurface image can be distorted because the velocity changes around interfaces. In this paper, we attempt to minimize the distortion by reducing reflection energy in the source and receiver wavefields through acoustic impedance homogenization. To make acoustic impedance constant, we define fake density model and use it for migration. When the acoustic impedance is constant over all layers, the reflection coefficient at normal incidence becomes zero and the minimized reflection energy results in the improvement of migration result. To verify our algorithm, we implement the reverse-time migration using cell-based finite-difference method. Through numerical examples, we can note that the migration image is improved at the layer interfaces with high velocity contrast, and it shows the marked improvement particularly in the shallow part.

• Geophysics and Geophysical Exploration
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• v.13 no.4
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• pp.315-322
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• 2010

The phase-screen and the split-step Fourier migrations, which are implemented in both the frequency-wavenumber and frequency-space domains by using one-way scalar wave equation, allow imaging in laterally heterogeneous media with less computing time and efficiency. The generalized-screen migration employs the series expansion of the exponential, unlike the phase-screen and the split-step Fourier migrations which assume the vertical propagation in frequency-wavenumber domain. In addition, since the generalized-screen migration generalizes the series expansion of the vertical slowness, it can utilize higher-order terms of that series expansion. As a result, the generalized-screen migration has higher accuracy in computing the propagation with wide angles than the phase-screen and split-step Fourier migrations for media with large and rapid lateral velocity variations. In this study, we developed a 2D prestack generalized-screen migration module for imaging a complex subsurface efficiently, which includes various dips and large lateral variations. We compared the generalized-screen propagator with the phase-screen propagator for a constant perturbation model and the SEG/EAGE salt dome model. The generalized-screen propagator was more accurate than the phase-screen propagator in computing the propagation with wide angles. Furthermore, the more the higher-order terms were added for the generalized-screen propagator, the more the accuracy was increased. Finally, we compared the results of the generalizedscreen migration with those of the phase-screen migration for a model which included various dips and large lateral velocity variations and the synthetic data of the SEG/EAGE salt dome model. In the generalized-screen migration section, reflectors were positioned more accurately than in the phase-screen migration section.

• Journal of the Korea Society of Computer and Information
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• v.16 no.11
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• pp.123-135
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• 2011

The domestic market of database in Korea is estimated to be over 3.663 trillion won. The data migration is getting to be more important along with the continuous growth of the database industry. g-CRM and private recommending function are examples of the service that can be given through coupling among customer database, product database, geographic information database, and others. The core infrastructure is also the database which is integrated, perfect, and reliable. There are not enough researches on efficient way of data migration and integrating process and investigation of migrated data though trends of database in IT environment as above. In connection with this issue, we have made a model for data migration on scientific and technological contents and suggest the result of data migration process adapting that model. In addition, we verified migration's exhaustiveness, migration's consistency, and migration's coherence for investigation of migrated data and database. From the result, we conclude data migration based on proper model has a significant influence on the database consistency and the data values correctness and is essential to maintain high qualified database.

• Journal of the Korean Geographical Society
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• v.46 no.2
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• pp.212-232
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• 2011

The main objective of this study is to establish a population projection method based on the biregional cohort-component method and to apply it to population projections for Busan. Some drawbacks of using the net migration cohort-component method in a regional or local level population projection are demonstrated. A biregional cohort-component method, a variant of the interregional cohort-component method, is established as an alternative where in-migration and out-migration are separately considered and then are combined to produce a projection for the migration component. Predicated on the established method, population projections for Busan are undertaken for the period of 2005~2030 under three different scenarios. Considerably different projection results are obtained between the net migration and biregional methods; among others, the trend of population decline is more severe in the former than in the latter. An investigation of the temporal trend of the projected population shows that the proposed method is highly reasonable. In conclusion, the proposed method based on the biregional cohort-component method seems not only to be theoretically more robust than the net migration cohort-component method but also to be very effective in the real world application.

• International Area Studies Review
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• v.21 no.4
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• pp.125-139
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• 2017

This study analyzes the determinants and patterns of regional migration in Myanmar. Population migration is affected by various factors such as economic and social factors as well as regional characteristics. It is affected by factors such as income, employment and social overhead capital. Therefore, this study attempts to analyze the following two research problems. First, I would like to analyze whether the reform and opening of Myanmar is causing the migration of rural to urban population. Myanmar is also trying to verify the pattern of population migration experienced by other developing countries. Second, we analyze the impact of social overhead capital on population migration in Myanmar. We analyze the impact of basic infrastructure such as roads, electricity and water on population movements. This will give implications for investment policy decision of social overhead capital for balanced regional development. First, the pattern of population migration in Myanmar is shifting from rural to urban areas, as other developing countries have experienced. Myanmar's urban areas of Yangon and Mandalay have been analyzed as having migration. Second, the expansion of social overhead capital was found to have an impact. Social overhead capital such as roads and educational environments were analyzed to have the capacity to inhale the population. Especially, the educational environment of the region has a great effect on population migration. It is analyzed that education reform is an important policy issue for the balanced regional development of Myanmar. Fourth, employment opportunities were analyzed to have the greatest impact on Myanmar population movements. In the early stage of economic development, it is analyzed that the population moves to a region where employment opportunity is high in the situation where foreign capital is coming in. It is analyzed that the direction of inflow of foreign capital and the imbalance of development in the region will be determined in the situation where the economic development is carried out through foreign capital.

• International Journal of Stem Cells
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• v.16 no.2
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• pp.180-190
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• 2023

Background and Objectives: Regenerative endodontic procedures (REPs) are a research hotspot in the endodontic field. One of the biggest problems of REPs is that it is difficult to realize regeneration of pulp-dentin complex and functional reconstruction. The reason is still not clear. We hypothesize that the migration may be different in different dental stem cells. Periodontal ligament stem cells (PDLSCs) may migrate faster than stem cells of apical papilla (SCAPs), differentiating into cementum-like tissue, bone-like tissue and periodontal ligament-like tissue and, finally affecting the outcomes of REPs. Hence, this study aimed to explore the mechanism that regulates the migration of PDLSCs. Methods and Results: After isolating and culturing PDLSCs and SCAPs from human third molars, we compared the migration of PDLSCs and SCAPs. Then we investigated the role of SDF-1𝛼-CXCR4/CXCR7 axis in PDLSC migration. We further investigated the impact of Porphyromonas gingivalis (P. gingivalis) lipopolysaccharide (LPS) on PDLSC migration and the potential mechanism. PDLSCs showed better migration under both noninflammatory and inflammatory conditions than SCAPs. SDF-1𝛼 can promote the migration of PDLSCs by elevating the expression of CXCR4 and CXCR7, increasing the interaction between them, promoting expression of 𝛽-arrestin1 and activating the ERK signaling pathway. P. gingivalis LPS can promote the migration of PDLSCs toward SDF-1𝛼 through increasing the expression of CXCR4 via the NF-𝜅B signaling pathway, promoting the expression of 𝛽-arrestin1, and activating the ERK signaling pathway. Conclusions: This study helped elucidate the potential reason for the difficulty in forming pulp-dentin complex.